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- Subject: misc.kids FAQ on Childhood Vaccinations, Part 2/4
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- =3D=3D=3D=3D
- Section 3. Specific vaccines
- ---------------------------------------------------------------------------=
- ----
- Section 3a. DTP (diptheria, pertussis, and tetanus) and DT
- [Last updated October 2. 1999.]=20
-
- Q3a.1 What is diptheria, and what are the risks of the disease?=20
-
- Diptheria is a contagious disease affecting the nose, throat, and skin. Com=
- plications include paralysis (about 20% of patients)
- and heart damage (about 50%) (Pantell, Fries, and Vickery). The Merck manua=
- l has a very long list of complications, mostly
- involving the heart, and says that complications are likely if antitoxin is=
- n't administered properly. The death rate was 35%
- before antitoxin was available, and is now 10% (Harrison).=20
-
- Q3a.2 How common was diptheria before routine vaccination, and how common i=
- s it now?=20
-
- In 1900, there were 40.3 deaths per 100,000 population from diptheria in th=
- e US. There was a sharp decline in the number of
- deaths per 100,000 both before and after routine vaccination was instituted=
- in the 1940s, and in 1990 there were 4 cases of
- diptheria reported in the US. (_Historical Statistics of the United States,=
- Colonial Times to 1970_ and _Statistical Abstracts of
- the United States_.=20
-
- In Europe, there were large diptheria epidemics during and after World War =
- II, with an estimated one million cases and 50 000
- deaths in 1943 (source: WHO web page on diptheria, written March 1998,
- http://www.who.org/gpv-dvacc/diseases/diphtheria_dis.htm). More recently, t=
- here have been large epidemics in Russia and the
- Newly Independent States.=20
-
- Q3a.3 How effective is the diptheria vaccine?=20
-
- "The fatality rate in immunized populations is one-tenth that in the unimmu=
- nized population. Paralysis is 5 times and 'malignant'
- disease 15 times less common in immune than in nonimmune individuals." (Har=
- rison)=20
-
- Q3a.4 How long does the diptheria vaccine last?=20
-
- Ten years.=20
-
- Q3a.5 What is pertussis, and what are the risks of the disease?=20
-
- Pertussis, or whooping cough, is a very contagious disease of the respirato=
- ry tract. Its attack rate in unvaccinated household
- contacts is over 90% (PDR) or up to 90 and in some cases 100% (Harrison).=
- =20
-
- Pertussis is very serious in children under 2, with a mortality rate on abo=
- ut 1 to 2%. (Merck) "Prior to the availability of a
- vaccine, pertussis caused as many deaths as all other contagious disease _c=
- ombined_." (Harrison, p. 607) Complications
- include various lung complications (The Merck Manual has a long list of the=
- se), cerebral complications, hemorrage into the
- brain, eyes, skin, and mucuous membranes. In addition to killing, it can le=
- ave surviving infants with lasting lung damage and
- neurological diseases.=20
-
- The mortality rate is higher in developing countries, partly because childr=
- en in these countries contract pertussis at a younger
- age (and mortality is higher at younger ages), and partly due to an associa=
- tion with protein-energy malnutrition (Galazka). This
- same article estimated that in the industrialized world, 0.04% of infected =
- children die from pertussis and complications, usually
- pneumonia "Among vaccine-preventable diseases, pertussis rivals measles and=
- neonatal tentanus in importance and severity in
- young children in developing countries and is third only to measles and neo=
- natal tetanus as a cause of death. It is estimated that
- pertussis is still causing some 340,000 deaths of children in the world eac=
- h year." (Galazka)=20
-
- Q3a.6 How common was pertussis before routine vaccination, and how common i=
- s it now?=20
-
- [Note: This section may be outdated, since the introduction of the new acel=
- lular vaccine has caused changed in vaccination
- schedules and vaccination coverage. More recent information on internationa=
- l vaccine schedules and disease incidence may be
- found at http://www.who.org.)=20
-
- "Since immunization against pertussis (whooping cough) became widespread, t=
- he number of reported cases and associated
- mortality declined from about 120,000 cases and 1,100 deaths in 1950, to an=
- annual rate of about 3,500 cases and 10
- fatalities in recent years." (PDR) For unknown reasons, there has been an i=
- ncrease in the US recently. "Over 6000 cases of
- pertussis were reported in the U.S. in 1993, the highest number in 25 years=
- ." (N Engl J Med 1994 Jul 7; 331:16-21,
- summarized in Journal Watch for July 22, 1994.) There is also a recent repo=
- rt (MMWR Nov 11, p. 807) of a strain of
- pertussis resistant to erythromycin.=20
-
- In some other countries, pertussis is more common (most of the following in=
- formation is taken from Galazka). "Before the
- introduction of widespread immunization of young children with pertussis va=
- ccine, the incidence rates in Europe and the United
- States were very high. The reported rates per 100,000 population ranged fro=
- m 200-300 in England and Wales and Sweden,
- to more than 1,000 in Denmark and Norway." (Galazka) Annual incidence in th=
- e US and Canada before the introduction of
- pertussis vaccine in the 1940s ranged from 98 to 210 per 100,000 population=
- . After the introduction and widespread use of
- DTP vaccine, incidence declined dramatically in most countries, and this tr=
- end continued for about 20 years. For example, in
- England and Wales, more than 150,000 cases of pertussis were reported a yea=
- r in the 1950s; by 1973, when vaccine
- acceptance was over 80%, only about 2,400 cases were reported.=20
-
- However, in the late 1970s and the 1980s, different trends began to appear =
- in different European countries. In one group of
- countries, reported incidence is between 10 and >100 per 100,000. This grou=
- p includes Sweden and Italy, which don't
- routinely give pertussis vaccine to infants. It also includes Germany, the =
- former USSR, Ireland, Spain, and the United
- Kingdom, where infants are routinely vaccinated, but coverage is less than =
- 80%. In Denmark, incidence is high despite high
- coverage, but Denmark uses a different vaccination schedule from the other =
- countries. Countries with a moderate reported
- incidence (between 1 and 10 per 100,000) include Austria, Finland, Greece, =
- Israel, Norway, the Netherlands, Portugal,
- Romania, and Yugoslavia. Countries with a low incidence (less than 1 per 10=
- 0,000) include Hungary, Switzerland, Bulgaria,
- Czechoslovakia, Poland, and Turkey.=20
-
- Q3a.7 How effective is the whole cell pertussis vaccine?=20
-
- It's one of the less effective childhood vaccinations. The PDR estimates it=
- s effectiveness at 70-80%. It's effectiveness rating
- depends on the severity of the cases of pertussis being observed. One study=
- of 1797 households found the vaccine to be 64%
- effective against a mild cough, 81% effective against a paroxysmal cough, a=
- nd 95% effective against severe clinical illness.
- "Requiring laboratory confirmation improved efficacy to 95 to 98% for cultu=
- re-positive children and to 77% to 95% for
- culture- or serology-confirmed cases, depending on disease severity. Vaccin=
- e efficacy for typical paroxysmal cough increased
- from 44% for one diptheria, tetanus, and pertussis vaccine to 80% for four =
- or more doses." (Onorato, Wassilak, and Meade)
- The variation in estimates of efficacy may be because the more severe cases=
- were more likely to actually be pertussis, or it may
- be that the vaccine protects better against severe pertussis than against a=
- mild form of the disease. Note: these effectiveness
- ratings are for the older, whole cell pertussis vaccine. For information on=
- the effectiveness of the newer, acellular vaccines,
- which is generally comparable to that of the older whole cell vaccines, see=
- below.=20
-
- Q3a.8 How long does the pertussis vaccine last?=20
-
- It doesn't. According to _Harrison's Internal Medicine_, "the protection ..=
- . is transient, with minimal resistance being evident a
- decade later." However, the critical years for pertussis immunity are when =
- a child is young; the disease is not dangerous for
- adults. With introduction of the new, less reactogenic acellular vaccine, i=
- t is possible that boosters may eventually be given to
- adults. (This estimate is for the older, whole cell vaccine, but the newer =
- acellular vaccine is apparently at least as durable as the
- whole cell one was.)=20
-
- Q3a.9 What is tetanus, and what are the risks of the disease?=20
-
- Tetanus is very dangerous. Even with antibiotics, mortality can be 40% or h=
- igher (Pantell, Fries, and Vickery, Harrison).
- Tetanus bacteria and its spores are everywhere. Because tetanus is so ubiqu=
- itous, the only way to counter it is widespread
- vaccination.=20
-
- *************************************************************************
- From=20J Thompson (jet14@columbia.edu):
-
- The tetanus vaccine is actually against the tetanus toxin (a protein
- called tetanospasmin), rather than the bacterium alone. The bacterium
- doesn't really do much of significance, but the toxin it secretes can cause
- muscular spasms. Thus, antibiotic therapy is rather pointless in preventing
- the spasms, but it is given anyway. The administration of antitoxin (passiv=
- e
- immunity) is helpful. (see Harrison's, 13th ed., p. 635)
- The vaccine consists of what is called "tetanus toxoid," which is simpl=
- y
- a purified version of the toxin, which has been treated to render it
- ineffective as a toxin (but still immunogenic).
- *************************************************************************
-
- Q3a.10 How common was tetanus before routine vaccination, and how common is=
- it now?=20
-
- 300,000 to 500,000 cases are reported worldwide, with a mortality of about =
- 45%. In the US, there are about 100 cases a
- year, with a mortality of 40-60% (Harrison).=20
-
- Q3a.11 How effective is the tetanus vaccine?=20
-
- According to Taking Care of Your Child, "Tetanus is one of our best immuniz=
- ations.... Of all the vaccines available, tetanus
- comes closest to 100 percent effectiveness after the initial series of shot=
- s."=20
-
- Q3a.12 How long does the tetanus vaccine last?=20
-
- Generally ten years. In the case of a really dirty wound, a booster is reco=
- mmended if the person hasn't been vaccinated for
- tetanus within the last five years.=20
-
- Q3a.13 What are some of the risks of the DTP vaccine?=20
-
- DTP, particularly in its earlier form (with the whole cell pertussis compon=
- ent) is probably the most controversial of the
- childhood vaccines, because of risks associated with its pertussis componen=
- t. Anecdotal evidence has linked the vaccine with a
- variety of problems, including convulsions, physical collapse, brain damage=
- and SIDS. Supporters of the vaccine have argued
- that these problems are common in any case at the age at which children are=
- vaccinated for pertussis, and therefore are not
- necessarily effects of the vaccine.=20
-
- The association between DTP and SIDS has not been confirmed by further stud=
- y (see Q1.5 for a study which found the
- evidence to be against such an association). The story on brain damage is s=
- omewhat different. Criticism of the pertussis vaccine
- received some confirmation in 1976, when a large British study of all child=
- ren 2 to 36 months old in Britain found that 1 in
- 310,000 doses resulted in permanent brain damage.=20
-
- Critics argue that the rate of complications from the pertussis vaccine is =
- too high, and the effectiveness too low. Some argue
- that the decline in pertussis cases in this century has been an effect more=
- of improved sanitation than of the pertussis vaccine.
- The side effects of this vaccine have inspired groups critical of vaccinati=
- on in several countries, including the US, where the
- group Dissatisfied Parents Together (DPT) has lobbied Congress for changes =
- to laws about vaccination and set up its own
- vaccine information center.=20
-
- Supporters of the pertussis vaccine differ in their response to the British=
- study which linked pertussis to brain damage. Some
- say that further analysis indicates that a link between the vaccine and bra=
- in damage is not so clear. "Meticulous reexamination
- of the data from this study led to the conclusion that the preliminary resu=
- lts were due to a systematic bias that favored finding an
- association between the vaccine and serious neurological sequelae. In fact,=
- there was no valid evidence from the study that the
- vaccine was associated with permanent neurological damage." (Shapiro)=20
-
- Some smaller studies done since the British study didn't find a connection =
- between DTP vaccine and neurological damage, and
- a new study was just published in the Journal of the American Medical Assoc=
- iation which finds no increased risk of serious
- neurological illness. I haven't seen the article yet, so my information com=
- es from the January 11, 1994 San Jose Mercury (from
- the New York Times news service), which reports that the study is in the cu=
- rrent (as of 1/11/94) issue of JAMA. According to
- the article, "The federally financed study, the largest of its kind in the =
- United States, involved 218,000 children up to 24 months
- old in Oregon and Washington who were studied for a one-year period, beginn=
- ing Aug. 1, 1987." However, the study is also
- described as "not intended to give a definitive answer to the question of w=
- hether whooping cough vaccine causes neurological
- illness."=20
-
- Others do not dispute the 1976 British study, but argue that a 1 in 310,000=
- risk of brain damage is still much smaller than the
- risk of actually getting pertussis. Supporters agree that it is important t=
- o maintain high vaccination levels against pertussis, lest
- we see a resurgence in the disease. In Great Britain, Japan, and Sweden, th=
- ere were sharp increases in the number of cases of
- pertussis when vaccination levels fell. Routine use was discontinued in Swe=
- den as a result of reports of side effects, while
- acceptance in Great Britain declined to 30% (Harrison), and vaccination dec=
- lined in Japan as well. "Within two years, one
- hundred thousand cases (with twenty-eight deaths) appeared in Great Britain=
- and thirteen thousand cases (with forty-one
- deaths) in Japan. Even in the US, the disease has by no means been wiped ou=
- t; there are still about fifteen hundred to two
- thousand cases (with four to ten deaths) each year. That is why virtually a=
- ll health care authorities recommend that we keep
- using this vaccine." (UC Berkeley)=20
-
- ACIP considered the available data on brain damage in 1991, and concluded t=
- hat "Subsequent studies have failed to provide
- evidence to support a causal relation between DTP vaccination and either se=
- rious acute neurologic illness or permanent
- neurologic injury." It further noted that "The risk estimate from the NCES =
- study of 1:330,000 for brain damage should no
- longer be considered valid on the basis of continuing analysis of the NCES =
- and other studies." (Staff, Diptheria, tetanus, and
- pertussis: recommendations for vaccine use and other preventive measures, i=
- n Recommendations of the Advisory Committee
- on Immunization Practices (ACIP). Aug 8, 1991, CDC: Atlanta. p. 1-21.)=20
-
- Known and non-controversial (i.e. everyone agrees that they occur) side eff=
- ects of DTP vaccine include redness and
- tenderness at the injection site, fever, drowsiness, fretfulness, vomiting,=
- and convulsions. (A vaccine information pamphlet from
- Kaiser gave the frequency as being 1 in 100 to 1 in 1000 for crying without=
- stopping for three hours or longer, a temperature
- of 105 F or greater, or an unusual, high-pitched cry, and 1 in 1,750 for co=
- nvulsions, generally from high fever, or shock
- collapse. I didn't see any frequencies in the PDR, other than describing th=
- ese side effects as rare.) It is a good idea to give
- acetaminophen to children being vaccinated for pertussis, to reduce the cha=
- nce of fever and febrile convulsions.=20
-
- From=20Mike Dedek:
-
- *************************************************************************
- American Journal of Diseases of Children 1992; 146: 173-176, February 1992,=
- =20
- "Pertussis outbreaks in Groups Claiming Religious Exemptions to Vaccination=
- s",=20
- Etkind, Lett, et. al.:
-
- 2% non-vaccinated students are monitored>
- :
- Key measures in preventing pertussis are immunization and judicious use of
- prophylactic antibiotics. Pertussis can be prevented in children by
- immunization. Unfortunately, controversy over the safety of the pertussis
- vaccine has reduced acceptance. Highly publicized accounts of reactions t=
- o the
- vaccine and a dramatic increase in the number of malpractice lawsuits have=
- made
- physicians and parents wary of using the diphtheria-tetanus toxoid and per=
- tussis
- vaccine. {n4-n6} This publicity may have caused overinterpretation of the
- guidelines for medical contraindications. {n7} However, this overinterpret=
- ation
- creates its own risk for malpractice if a child given an inappropriate med=
- ical
- contraindication suffers damage due to disease.
- *************************************************************************
-
- Q3a.14 Did SIDS disappear in Japan after the Japanese changed their pertuss=
- is vaccination policy in 1975?=20
-
- This claim is examined at length by Lon Morgan, DC,DABCO in his Web site "A=
- summary of JAPAN, SIDS, and
- PERTUSSIS IMMUNIZATION" at http://fp1.cyberhighway.net/~lmorgan/fearmongers=
- /japan_sids.htm. It turns out that what
- went away, in 1975, when Japan increased the age at which it administered t=
- he first dose of the vaccine from three months to
- two years, was *claims of vaccine injuries* for SIDS. Japan had a compensat=
- ion system for vaccine injuries, in which claims
- were to be paid unless other causes were clearly provable. Under this syste=
- m, 11 claims were paid for what was termed
- Sudden Death, between 1970-1975 (this out of 25-30 million doses of pertuss=
- is vaccine). After the vaccination age was
- raised, no further claims were paid for Sudden Death related to vaccination=
- . Since SIDS occurs before 12 months of age, any
- cases of SIDS can not be attributed to a vaccine which is given starting at=
- 24 months.=20
-
- Japan has, however, kept statistics for SIDS, and these statistics showed t=
- he numbers of SIDS cases *increasing*, rather than
- decreasing, at the time that the age of the first pertussis vaccination was=
- raised. Though the delay in age for the first pertussis
- vaccination did not reduce the incidence of SIDS, it did result in a huge i=
- ncrease in pertussis cases, peaking at 13,105 cases
- and 41 deaths by 1979. For more details, and references, see Lon Morgan's s=
- ite.=20
-
- As a side note, recent vaccination rates for Japan, as listed in http://www=
- .who.int/gpv-surv/country/japan.html, were, in 1996,
- 98% for polio, 100% for diptheria, pertussis, and tetanus, and 94% for meas=
- les; the coverage for BCG in 1993 was 91%.=20
-
- Q3a.15 When is the DTP vaccine contraindicated?=20
-
- Hypersensitivity to a vaccine component, including thimerosal, a mercury de=
- rivative. Defer vaccination in case of fever or acute
- infection (but not nececcarily for a mild cold without a fever). A history =
- of convulsions is generally a contraindication to
- pertussis vaccination, but "The ACIP and AAP recognize certain circumstance=
- s in which children with stable central nervous
- system disorders, including well-controlled seizures or satisfactorily expl=
- ained single seizures, may receive pertussis vaccine.
- The ACIP and AAP do not consider a family history of seizures to be a contr=
- aindication to pertussis vaccine." (PDR)=20
-
- The following reactions to a previous dose are contraindications: An immedi=
- ate anapylactic reaction. Encephalopathy occuring
- within 7 days following DTP vaccination. Precautions include a fever of >=
- =3D 40.5 C (105 F) within 48 hours, collapse of
- shocklike state within 48 hours, persistent inconsolable crying for more th=
- an 3 hours within 48 hours, convulsions with or
- without fever within 3 days. (These latter are precautions rather than cont=
- raindications, because there might be circumstances,
- such as a pertussis epidemic, where you would still want to give the vaccin=
- e.)=20
-
- Pertussis vaccine should not be given to anyone over seven years old (this =
- may change, in time, with the new acellular vaccine,
- but further study is needed first).=20
-
- Vaccine components capable of causing adverse reactions: for diptheria, thi=
- merosal and toxoid; for tetanus, thimerosal and
- toxoid; for pertussis, bacterial components (Travel Medicine Advisor).=20
-
- (Note: There is currently, as of 1999, a move toward replacing thimerosal i=
- n vaccines, so the reference to thimerosal here may
- shortly be out of date.)=20
-
- Q3a.16 What are the advantages and disadvantages of the new acellular pertu=
- ssis vaccine?=20
-
- The big advantage is that the acellular vaccine has fewer side effects. The=
- FDA initially held off on approving it for the earlier
- shots (while approving it for the fourth and fifth shots), mainly due to re=
- maining uncertainty as to whether it is as effective as the
- whole cell vaccine. Reports from Japan indicated that it is, but a Swedish =
- clinical trial indicated efficacy of 59% for one, and
- 64% for the other acellular vaccine. However, even this trial did show >90%=
- efficacy against severe pertussis. (Shapiro) More
- recent results in Sweden and Italy indicate it is both safe and effective. =
- On July 31, 1996, the FDA licensed one acellular
- pertussis vaccine for the inital three shots, and more followed. The Americ=
- an Association of Pediatrics has issued guidelines for
- the use of the new vaccine, which can be found at their web page, http://ww=
- w.aap.org.=20
-
- As of 7/14/95, results were available from two large European studies, invo=
- lving 9,829 infants in Sweden and 15,601 infants in
- Italy. The National Institute of Allergy and Infectious Disease (in the US)=
- reported that "three similar experimental vaccines
- effectively immunized 84% to 85% of the children in the trials, while resul=
- ting in fewer side effects than current, widely used
- versions." (Wall Street Journal, 7/14/95, p. A7A) A surprising result of th=
- e studies was that whole cell pertussis vaccine
- efficacy rates were lower than usual: "conventional vaccines provided prote=
- ction for just 36% of children in Italy and 48% in
- Sweden. In the US the conventional vaccine proves effective in 70% to 95% o=
- f the children who are vaccinated." Officials
- suggested that infants in these studies might have had a higher intensity o=
- f exposure to the bacteria due to the lack of
- widespread vaccination in those countries, and that might explain the lower=
- efficacy. A fourth acellular vaccine provided
- protection in 58% of the cases. The high efficacy and low side effects show=
- n for the acellular pertussis vaccine in these studies
- will likely lead to requests that the FDA also approve the acellular vaccin=
- e for the earlier pertusis shots. More information on
- recent study results can be found in NEJM, Vol. 333, Number 16, Oct. 19, 19=
- 95 (B. Trollfors and others).=20
-
- From=20Mike Dedek:
-
- This next one indicates there's a better vaccine that may soon become
- available [Note: this vaccine is now available, and recommended for
- all doses in the US and some industrialized countries]:
-
- *************************************************************************
- In Pediatrics 1992; 89; 882-887, May 1992, "Acellular Pertussis Vaccination
- of 2-Month Old Infants in the United States", Pichichero, Francis, et. at.:
-
- ABSTRACT: This is the first study in children from the United States that
- evaluates the immunogenicity of and adverse reactions to the Connaught/Bike=
- n
- two-component acellular pertussis vaccine compared with whole-cell pertu=
- ssis
- vaccine when given as a primary immunization series at 2, 4, and 6 months o=
- f
- age. Three hundred eighty infants were studied; 285 received acellular
- diphtheria-tetanus toxoids- pertussis (DTP (ADTP)) and 95 received whole-c=
- ell
- DTP (WDTP). Following the third dose, ADTP vaccination produced higher ant=
- ibody
- responses than WDTP to lymphocytosis-promoting factor (enzyme-linked
- immunosorbent assay IgG geometric mean titer (GMT) =3D 131 vs 9 and Chinese
- hamster ovary cell assay GMT =3D 273 vs 16) and to filamentous hemagglutini=
- n (IgG
- GMT =3D 73 vs 10) (all P < .0001). Agglutinin responses were higher in WDT=
- P
- compared with ADTP recipients (GMT =3D 50 vs 37; P =3D .02). Local reactio=
- ns were
- fewer for all three doses following ADTP vaccination. Fever, irritability,
- drowsiness, anorexia, vomiting, and unusual crying all occurred less freque=
- ntly
- in ADTP compared with WDTP recipients for one or more of the three doses. =
- We
- conclude that this two-component ADTP vaccine when given as a primary serie=
- s
- produces greater immunogenicity and fewer adverse effects than the currentl=
- y
- licensed WDTP vaccine.
-
- ...A large case-control study
- in Britain (National Childhood Encephalopathy Study) estimated that permane=
- nt
- neurologic deficits may occur after its administration in 1 in 310000 doses
- of WDTP. However, a reanalysis of this and similar studies recently has le=
- d=20
- to the widely held conclusion that a causal association between WDTP vaccin=
- ation
- and permanent brain damage has not been demonstrated....
-
- *************************************************************************
- Public Health Rep 1992; 107: 365-366, May 1992/June 1992, "FDA Approves New
- Whooping Cough Vaccine"
-
- The Food and Drug Administration (FDA) has licensed a new whooping co=
- ugh
- vaccine that may cause fewer side effects in children.
-
- The new vaccine is being approved at this time only for the fourth an=
- d
- fifth shots. The current vaccine will continue to be used for the first t=
- hree
- shots. Additional research has been undertaken to ascertain whether it wi=
- ll be
- effective for preventing pertussis when used for primary inmunization --=
- the
- first three shots -- in infants.
-
- The new vaccine is acellular, meaning that it is made from only part o=
- f the
- pertussis organism, as opposed to the whole organism from which the curre=
- nt
- vaccine is derived.
-
- Whooping cough ( pertussis) is a highly contagious disease. As many as=
- 90
- percent of nonimmune household contacts acquire the infection. Since rout=
- ine
- immunization against pertussis became common in the United States, the n=
- umber
- of reported cases of disease and deaths from it has declined from about 12=
- 0,000
- cases with 1,100 deaths in 1950 to an annual average in recent years of ab=
- out
- 3,500 cases with 10 fatalities.
-
- The new vaccine appears to be as effective in older children as the cu=
- rrent
- vaccine and to cause fewer adverse reactions. It has been widely used in =
- Japan
- -- where it was developed -- with apparent success in children older than =
- 2
- years. It will be combined with diphtheria and tetanus toxoids (DTP) and =
- sold
- under the brand name Acel-Imune.
-
- Gerald Quinnan, MD, acting director of FDA's Center for Biologics, where=
- the
- vaccine was evaluated and licensed, said that the availability of an acell=
- ular
- vaccine is a significant step forward in infectious disease control.
-
- The most common adverse reactions seen in clinical trials of the acellula=
- r
- pertussis vaccine included tenderness, redness, and swelling at the injec=
- tion
- site, fever, drowsiness, fretfulness, and vomiting.
-
- The new pertussis vaccine component is produced by Takeda Chemical
- Industries Ltd. of Osaka, Japan, and is combined with diphtheria and tetan=
- us
- toxoids manufactured by Lederle Laboratories of Wayne, NJ. Lederle will a=
- lso
- distribute the product in the United States. The vaccine is administered =
- by
- injection.
-
- The approval of the new vaccine comes at a time when the Federal Govern=
- ment
- is emphasizing early childhood immunizations in the wake of the largest rep=
- orted
- measles outbreak in the nation in 20 years -- with more than 27,600 cases a=
- nd 89
- deaths reported in 1990.
-
- The aim is to reach a goal of full immunization for 90 percent of childre=
- n by
- the time they are 2 years old.
- *************************************************************************
-
- As of September 1999, results are available from still more studies. Since =
- 1991, seven studies in Europe and Africa evaluated
- the efficacy of eight DTaP vaccines given to infants. The vaccines were by =
- different manufacturers, with varying number and
- quantity of antigens. Number of doses varied (three in some, four in others=
- ), as did other aspects of the study design, such as
- the case definition for pertussis and the laboratory method used to confirm=
- the diagnosis. For this reason, the studies can't be
- compared directly, but within the individual studies, the efficacy of whole=
- cell vaccine can be compared with the efficacy of
- acellular. Acellular was within the range expected for whole cell. Estimate=
- s of efficacy ranged from 59% to 89%. More serious
- adverse effects (fever over 105 F, persistent crying for more than three ho=
- urs, hypotonic hyporesponsive episodes, and
- seizures) happened less often with acellular. Really rare adverse events (e=
- ncephalopathy and anaphylactic shock) were too rare
- to show up in these studies. Acellular pertussis vaccines have also been us=
- ed routinely since 1981 in Japan.=20
-
- Despite the acellular vaccine's comparable efficacy and few adverse reactio=
- ns, the whole cell pertussis vaccine retains one
- advantage which ensures some continued use. It is cheaper, and more organiz=
- ations know how to make it In developing
- countries, where pertussis is a major killer, and money for vaccines in sho=
- rt supply, it is not clear that the advantages of the
- acellular vaccine justify the additional cost.=20
-
- Q3a.17 What are some of the risks of the DT (diptheria and tetanus) vaccine=
- ?=20
-
- Most of the risk in the DTP vaccine comes from its pertussis component; the=
- diptheria and tetanus vaccines are quite safe.
- Reactions to the diptheria vaccine are quite rare. Most reactions are local=
- , limited to swelling at the injection site. The same is
- true of the tetanus shot. "Severe local reactions can occur if too many sho=
- ts are received; this phenomenon was frequently seen
- in military recruits who received unneeded immunizations." (Pantell, Fries,=
- and Vickery)=20
-
- Q3a.18 When is the DT vaccine contraindicated?=20
-
- Should be avoided during the first trimester of pregnancy. People who have =
- had a reaction (which is very rare) should avoid it.=20
-
- Vaccine components capable of causing adverse reactions: for diptheria, thi=
- merosal and toxoid; for tetanus, thimerosal and
- toxoid (Travel Medicine Advisor).=20
-
- (Note: There is currently, as of 1999, a move toward replacing thimerosal i=
- n vaccines, so the reference to thimerosal here may
- shortly be out of date.)=20
-
- Q3a.19 Under what circumstances is tetanus toxoid given to pregnant women?=
- =20
-
- Tetanus toxoid is given to pregnant women in countries where there is a hig=
- h risk of neonatal tetanus (due to factors which
- enhance the risk of cord contamination in these countries).=20
-
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D
- Section 3b. Polio
- [This section last updated September 19, 1999.]
-
- Q3b.1 What is polio, and what are the risks of the disease?=20
-
- Polio is a contagious viral disease which crippled tens of thousands in the=
- 1950s, and killed more than a thousand a year.
- Because it is a mild gastrointestinal illness in young children and a serio=
- us paralytic illness in older people, it had an unusual
- epidemiology, with more cases of paralytic polio turning up in wealthy area=
- s and as sanitation improved. 80-90% of cases of
- polio are the minor illness; the rest are paralytic poliomyelitis. In paral=
- ytic poliomyelitis, < 25% suffer permanent severe
- disability, about 25% have mild disabilities, and > 50% recover with no res=
- idual paralysis. Mortality is 1 to 4%. "Recently, a
- post poliomyelitis syndrome has been described, characterized by muscle fat=
- igue and decreased endurance... The syndrome
- occurs many years after an attack of paralytic poliomyelitis..." (Merck).=
- =20
-
- Q3b.2 How effective is the polio vaccine?=20
-
- The Merck Manual and the Physician's Desk Reference give its effectiveness =
- as 95%. An article in a WHO publication (Hull
- and Ward) estimates effectiveness at 80%. (As with other WHO estimates, the=
- lower effectiveness rating reflects an estimate
- of effectiveness in the field in a variety of countries, including countrie=
- s in the Third World. Polio vaccine effectiveness can
- deteriorate if it is exposed to too much heat, which can happen in vaccinat=
- ion programs in some countries.)=20
-
- Q3b.3 How long does the polio vaccine last?=20
-
- It provides lifelong immunity.=20
-
- Q3b.4 What is the difference between oral polio vaccine (OPV) and inactivat=
- ed polio vaccine (IPV)?=20
-
- Oral polio vaccine provides better immunity, and was until recently usually=
- the recommended form, "because induces intestinal
- immunity, is simple to administer, is well accepted by patients, results in=
- immunization of some contacts of vaccinated persons,
- and has a record of having essentially eliminated disease associated with w=
- ild poliovirus in this country." (PDR) However, it
- carries a small risk of paralysis (see the answer to the next question for =
- details).=20
-
- Recently, with increased progress in worldwide eradication of polio, both A=
- CIP and AAP have changed their recommendation
- to IPV for all shots. OPV remains the vaccine of choice for countries where=
- polio is still endemic, and for people who will be
- shortly travelling to such countries.=20
-
- Q3b.5 I've heard that it is possible to contract polio from handling the di=
- apers of recently immunized infants. How long after
- receiving the vaccine does the child's excrement continue to contain the vi=
- rus?=20
-
- *************************************************************************
- From=20Caren Feldman:
-
- > Speaking of this, I know there has been mention in the past of contractin=
- g
- > polio from handling diapers of recently immunized infants. Does anyone
- > know how long after receiving the vaccine the child's excrement continues=
- to
- > contain the virus? The reason I ask is because sean got his polio booste=
- r
- > and Rachel has only received the first vaccine in the series. The doctor=
- 's
- > office said she wain no danger of contracting poliofrom him since they do=
- n't
- > come in contact with each other *that* closely. However, I have to be ex=
- tra
- > careful after helping Sean clean up (he needs help sometimes) or handling=
- his
- > underwear to make sure I wash my hands thoroughly. So, how long until I
- > can stop being paranoid about remembering to wash my hands after handling
- > the laundry? (I forgot to ask)
- >=20
- The short answer is 6 weeks. But since you brought up the subject...here's =
- what
- I fond out about polio immunizations:
-
- When I had read one poster's response that the live polio virus from feces
- was actually weakened virus that would in fact help immunize unimmunized ki=
- ds
- they'd come in contact with it, naturally I didn't believe it. Well, not at
- first. But I had enough doubts of my disbelief to start asking around, and =
- came
- up with some (at least to me) little known facts about polio and polio
- immunizations. I am presenting it to misc.kids for everyone's edification.
-
- Indeed, live virus from a recently immunized child's feces is weakened viru=
- s
- that health officials actually hope unimmunized kids come in contact with =
- to
- provide them with individual immunity and the general population with "herd=
- "
- immunity.
-
- Now here's the tricky part. One of the attenuated strains used to make the
- vaccine has a very low but existing back mutation rate, back to the "wild
- type", i.e. back to "regular" polio. If the weakened virus the child has be=
- en
- given mutates back to wild-type polio, any adult with no immunity to it (or
- an immunized adult for whom the immunization series did not "take") is
- potentially at risk for full blown polio. Of course, people with weak immun=
- e
- systems may be at risk even from weakened virus. Steroid use may also caus=
- e
- the immune system to weaken (besides the usual anti-rejection drugs, HIV,
- leukemia) and thus increase susceptibility for contracting the virus.
-
- Polio in young children manifests itself as a mild gastrointestinal ailment=
- .
- Polio in older children and adults starts as a mild gastroenteritis but wit=
- h
- complications that may lead to paralysis. Before the advent of improved pub=
- lic
- sanitation, most young children were exposed to and probably contracted the
- polio virus, so by adulthood, chances were everyone had immunity to it. It
- was only when public sanitation improved to where exposure to the virus was
- delayed until later childhood that polio epidemics became prevelant. Polio
- outbreaks in the US were less frequent among poor children than among more=
- =20
- affluent families.
-
- The CDC estimates the chances of getting polio from a first immunization (I
- presume this means gastroenteritis symptoms in babies, not paralytic polio)
- is one in half million. The chances of getting polio from subsequent
- immunizations is 1 in 12 million. I assume the chances of secondarily
- contracting polio from feces are even rarer.
-
- These rare cases probably account for the supermarket tabloid (not to menti=
- on
- "60 Minutes") stories of adults catching polio from recently immunized kids
- who'd been given oral vaccine. For those in the US, you will be glad to
- hear that a federal compensation program exists, called the National Vaccin=
- e
- Injury Compensation Program, to help those stricken with paralytic polio as=
- a
- result of coming into contact with a recipient of the oral polio vaccine.
-
-
- Thanks go to two posters on sci.med for answering my questions regarding th=
- is
- subject.
- *************************************************************************
-
- The 1993 Physician's Desk Reference confirms Caren Feldman's account, with =
- two small modifications. First, it gives the time
- when the virus is shed as 6-8 weeks, rather than six. Second, the CDC estim=
- ates which she gives are the estimates for cases of
- paralysis in *both* vaccine recipients and contacts of vaccine recipients c=
- ombined, not for recipients alone.=20
-
- Q3b.6 What are some other risks of the polio vaccine?=20
-
- A small risk of anaphylactic shock.=20
-
- Q3b.7 When is the polio vaccine contraindicated?=20
-
- Because of the small risk of paralytic polio in recipients and contact of r=
- ecipients of OPV, it should not be given to anyone who
- is immune-compromised or who has immune-compromised family members. (The PD=
- R has a really long list of immune
- deficiencies involved, which you can check if you think anyone in your fami=
- ly falls in this category.) In these cases, IPV should
- be given instead. IPV is also recommended for adults who are at risk for po=
- lio (such as unvaccinated adults travelling to an
- area where polio is endemic). Both vaccines are contraindicated for people =
- with an anaphylactic allergy to neomycin or
- streptomycin.=20
-
- Vaccine components capable of causing adverse reactions: for both OPV and I=
- PV, streptomycin, neomycin, and phenol red;
- for IPV, animal protein, formaldehyde, and polymyxin B (Travel Medicine Adv=
- isor).=20
-
- Q3b.8 Isn't it true that wild polio has been eliminated in the US?=20
-
- From=20Mike Dedek:
-
- *************************************************************************
- >From The Reuter Library Report, 2/26/93, "U.N. Warns on need for Polio=20
- Immunisation" copyright 1993 Reuters:
-
- The last outbreak of polio took place in the Netherlands 15 years ago. T=
- he
- virus was carried to Canada and the United States by infected people visit=
- ing
- their relatives, the WHO said. This caused the United States' last polio
- outbreak which hit the Amish community in the state of Pennsylvania in 1=
- 979.
-
- *************************************************************************
- >From The [London] Independent, 2/9/93, pg. 12, "Why child vaccines may be =
- a
- shot in the dark", by Tessa Thomas:
-
- After numerous cases in which the ''live'' oral polio vaccination was
- found to have caused the disease, the American government is considering
- reintroducing the inactivated injectable version. In the UK, the Departmen=
- t of
- Health advocates the live version on the basis that it deactivates any wil=
- d
- polio virus that reaches the gut, preventing it being excreted into the
- community, thus conferring community protection. The injectable vaccine ac=
- ts
- only on the bloodstream, protecting the individual but not breaking the ch=
- ain of
- infection. Lobbying by the Association of Parents of Vaccine Damaged Child=
- ren
- has prompted an acknowledgement by Virginia Bottomley, the Secretary of St=
- ate
- for Health, that the live vaccine is responsible for 50 per cent of recent=
- new
- cases of polio. Between 1978 and 1991 there were 42 cases of polio, 18 =
- of
- which followed vaccination and nine of which followed infection through co=
- ntact
- with the vaccinated child.
-
- *************************************************************************
- The Atlanta Journal and Constitution, 12/19/92, "Cases in Netherlands put
- Americas at risk for polio", by Steve Sternberg, Section E; pg. 1
-
- The last polio case in the Americas emerged on Aug. 23, 1991 in the remot=
- e
- Peruvian highlands village of Pichinaki...
-
- *************************************************************************
- UPI 12/10/92:
-
- Except for a few rare vaccine-associated cases, there have been no cas=
- es
- of polio in the United States since 1986 when there was one imported ca=
- se.
- The current vaccine, Sutter said, is close to 100 percent effective in
- preventing the disease.
-
- *************************************************************************
-
- MMWR's Summary of Notifiable Diseases, United States, 1997 (MMWR, November =
- 20, 1998 / 46(54);1-87) reports that
- "Since 1980, a total of 147 cases have been reported, of which 139 were ass=
- ociated with the use of OPV. The last imported
- case was reported in 1993."=20
-
- Q3b.9 Why are we still vaccinating for polio, then?=20
-
- The AAP and ACIP continue to recommend vaccination for polio for several re=
- asons. First, the risk of the disease is much
- higher than the risk of the vaccine. Second, though there is no wild polio =
- in the US *now*, with high levels of vaccination, there
- is still polio elsewhere in the world. 148,000 cases were reported to WHO i=
- n 1990. China reported 5,065 cases. The USSR
- reported 337 cases. India reported 7,340. (Hull and Ward) There have been s=
- everal outbreaks of polio in countries 2 or more
- years after the last reported case of polio. Importation from polio endemic=
- countries has led to outbreaks in Oman (1988-89
- and 1993), Jordan (1991-92), Malaysia (1992), and the Netherlands (1992-93)=
- (MMWR, reported in HICNet Medical
- News on 15 August 1994). Wild poliovirus type 3 was isolated during January=
- -February 1993 among members of a religious
- community objecting to vaccination in Canada (although no actual cases of p=
- arlytic polio occurred in Canada at this time).
- There is a concern that if levels of vaccination were reduced in the US, po=
- lio could be reintroduced, and we could see polio
- epidemics here again.=20
-
- Encouraged by the worldwide elimination of smallpox, WHO, in 1988, set a go=
- al of eradicating polio from the world by 2000.
- Since then, the number of cases in the world has declined dramatically (29,=
- 916 in 1989 and 16,435 in 1990), and the number
- of countries reporting 0 cases has increased (74 countries in 1985 and 116 =
- countries in 1990). As of 1993, the number of
- cases worldwide has falled to 9714, and nearly 70 percent of all countries =
- reported no cases. (Progress toward global
- eradication of poliomyelitis, 1988-1993. MMWR 1994 Jul 15; 43:499-503. Summ=
- arized in Journal Watch Summaries for July
- 22, 1994.) As of 1999, WHO reports still further progress, "In 1988, virus =
- circulated widely on all continents except Australia.
- By 1998, the Americas were polio-free (certification of eradication in 1994=
- ), transmission has been interrupted in the Western
- Pacific Region of WHO, including China, and in the European Region, except =
- for a small focus in south-east Turkey. As shown
- below, only three major foci of transmission remain: South Asia (Afghanista=
- n, Pakistan, India), West Africa (mainly Nigeria)
- and Central Africa (mainly Democratic Republic of Congo)." So another facto=
- r in the decision to continue vaccinating for polio
- is the hope that it can be eliminated for good.=20
-
- After much debate, the US has switched to IPV instead of OPV (IPV being les=
- s effective, but lower in side effects). The
- decision at first was to continue with OPV because it has been so successfu=
- l, the rate of side effects is still considered very low,
- and because of various advantages in producing immunity (see above). Accord=
- ing to the 1993 PDR, "The choice of OPV as
- the preferred poliovirus vaccine for primary administration to children in =
- the United States has been made by the ACIP, the
- Committee on Infectious Diseases of the American Academy of Pediatrics, and=
- a special expert committee of the Institute of
- Medicine, National Academy of Sciences." In 1995, though, that decision was=
- changed, and the injected vaccine became
- recommended for the first two polio shots. As progress toward worldwide pol=
- io eradication continued, and as the change in
- the vaccination schedule (from an oral to an injected form) did not result =
- in any decline in vaccination coverage, ACIP and
- AAP are now recommending IPV for all shots.=20
-
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D
- Section 3c. MMR (measles, mumps, and rubella)
- [This section last updated on October 23, 1999.]=20
-
- Q3c.1 What is measles, and what are the risks of the disease?=20
-
- Measles is one of the most contagious infectious diseases. "A child can cat=
- ch measles by breathing the air in a doctor's waiting
- room two hours after an infected child has left." (Fettner) 90% of suscepti=
- ble household contacts get the disease (Harrison).
- Measles spreads very rapidly in unexposed populations. In 1951, it was intr=
- oduced to Greenland by a recently arriaved visitor
- who went to a dance as he was coming down with it, and in three months it s=
- pread to more than 4000 cases and 72 deaths.
- The attack rate was 999 cases per 1000 people. In 1875, measles was introdu=
- ced to Fiji and killed 30 percent of the
- population (Smith).=20
-
- In areas where it was endemic, before the measles vaccine, measles epidemic=
- s used to occur at regular intervals of two to three
- years, usually in the spring, with small local outbreaks in intervening yea=
- rs. Mortality is low in healthy, well-nourished children
- unless complications ensue (Merck), but nevertheless there were 400 deaths =
- a year before an improved measles vaccine was
- introduced in 1966 (Pantell, Fries, and Vickery). Complications include bra=
- in infection, pneumonia, convulsions, blindness,
- various bacterial infections, encephalitis, and SSPE (a fatal complication =
- which can occur years after a person has had
- measles). Pregnant women who get measles have a 20% chance of miscarriage.=
- =20
-
- Worldwide, measles is one of the leading causes of childhood mortality. "Me=
- asles has been called the greatest killer of children
- in history." (Clements, Strassburg, Cutts, and Torel) In 1990, "45 million =
- cases and around 1 million deaths were estimated to
- occur in developing countries. Thus measles is still responsible for more d=
- eaths than any other EPI target diseases. The true
- number dying as a result of measles may be twice the estimated 1 million if=
- the recently documented delayed effect of the
- disease is taken into account." (Ibid.) Mortality is higher in developing c=
- ountries due to a difference in the age at which most
- people catch it (measles is a more dangerous disease in the very young), po=
- orer nutrition, less availability of treatment for
- bacterial chest infections, and other environmental factors. However, "Even=
- in countries with adequate health care and healthy
- child populations, the complication rate can reach 10%." (Ibid.)=20
-
- More information on the incidence of measles complications is found in the =
- answer to Q3c.2.=20
-
- Q3c.2 How common was measles before routine vaccination, and how common is =
- it now?=20
-
- *************************************************************************
- From=20Anthony C.:
-
- I havent finished reading this thread so pardon if someone else has
- already posted this information
-
- Rates of complications of measles and measles immunization
- Measles per 10^5 Vaccine per 10^5
- Encephalomylelitis 50-400 .1
- sspe .5-2.0 .05-.1
- Pneumonia 3800-1000 =20
- Seizures 500-1000 .02-19
- Deaths 10-10000 .01
-
- These statistics are worldwide, hence the variablility in numbers. The
- higher rates of pneumonia and death represent figures collected from
- India, Nambia, Nigeria, bangladesh and other countries with developing
- health care industries.
-
- As far as the number of people afflicted with measles in the US
- Cases Deaths
- 1963 385,566 364 Inactivated measles type vaccine available
- 1964 458,093 421
- 1966 204,136 261 public health administration of vaccine
- 1967 62,705 81
- 1968 22,231 24
- .
- .hovers around 20-70,000
- .
- 1977 57,345 15
- 1978 26,871 11
- 1979 13,597 6
- 1980 13,506 11
- 1981 3,032 2
- 1982 1,697 2
- 1983 1,497 4
- 1984 2,587 1
- 1985 2,822 4
- 1986 6,273 2
- 1987 3,588 2
- 1988 2,933 not available
- 1989 16,236 41
- 1990 26,520 97
-
- iMajor foci of retransmission barring the complete elimination of measles:
- 1) unimmunized indigent, inner city youngsters.
- 2) illegal aliens.
-
- I hope this is useful. My source is Zinsser microbiology, 20th edition
- pages 1013-1015, joklik et al.
- *************************************************************************
-
- As the above table shows, there was a marked increase in measles incidence =
- in the US from 1989 to 1991. This resulted in
- more than 50,000 cases including 125 deaths (http://www.immunize.org/nslt.d=
- /n21/paradx21.htm). Measles has been on the
- decline again in the US since 1990 (MMWR Feb 4, 1994, p. 57). Colleges enfo=
- rcing the requirement for a second measles
- vaccine report fewer measles outbreaks than schools with no requirement (JA=
- MA, Oct 12, 1994, p. 1127). (Both of these
- citations from Journal Watch for Jan 15, 1995 - paper edition, or Feb 7, 19=
- 95 - electronic edition.) During 1998, a provisional
- total of 100 measles cases was reported to the CDC, making for a record low=
- , 28% lower than the 138 cases reported in
- 1997 (MMWR 48(34);749-753, 1999. Centers for Disease Control).=20
-
- Q3c.3 How effective is the measles vaccine?=20
-
- The Merck Manual and the Physician's Desk Reference estimate its effectiven=
- ess at 95%. This estimate is based on studies of
- the immunity induced by a series of vaccinations beginning at 15 months. An=
- other article, estimating the immunity induced in
- field conditions (including some Third World countries, which may have less=
- reliable vaccine storage) by a series of injections
- beginning at 9 months (the injections are started earlier in areas where me=
- asles is widespread), estimated effectiveness as 85%
- (Clements, Strassburg, Cutts, and Torel).=20
-
- A recent article in Pediatric News (Imperio. Vaccine-Exempt At Higher Risk =
- For Measles. Pediatric News 33(9):9, 1999.)
- reported that "Individuals aged 5-19 years who were not vaccinated due to r=
- eligious or philosophical exemptions were, on
- average, 35 times more likely than vaccinated individuals to contract measl=
- es, according to a population-based, retrospective
- cohort study."=20
-
- Q3c.4 How long does the measles vaccine last?=20
-
- The Merck Manual describes it as "durable." The PDR says that all of the an=
- tibody levels induced by MMR have been shown
- to last up to 11 years without substantial decline, and "continued surveill=
- ance will be necessary to determine further duration of
- antibody persistance."=20
-
- Q3c.5 What are some of the risks of the measles vaccine?=20
-
- There is a small chance of complications similar to the complications of me=
- asles (pneumonia, encephalitis, SSPE). Information
- on the frequency of these complications is included in the answer to Q3c.2.=
- There is some risk of anaphylaxis. This risk is low;
- from the time that VAERS was instituted in 1990 till the publication of Upd=
- ate: Vaccine Side Effects, Adverse Reactions,
- Contraindications, and Precautions by ACIP in 1996, >70 million doses of MM=
- R vaccine had been distributed in the US, and
- only 33 cases of anaphylactic reactions had been reported to VAERS. It has =
- been traditionally believed that this risk is mainly
- for people allergic to eggs or neomycin. However, recent studies indicate t=
- hat anaphylactic reactions are not associated with
- egg allergies, but with some other component of the vaccine. There have bee=
- n some case reports, in the US and Japan, of
- anaphylactic reactions to the MMR vaccine in people with an anaphylactic se=
- nsitivity to gelatin.=20
-
- In rare instances, MMR vaccine can cause clinically apparent thrombocytopen=
- ia within 2 months after vaccination. Passive
- surveillance systems report an incidence of 1 case per 100,000 doses in Can=
- ada and France, and 1 per million in the US.
- Prospective studies have reported a range from 1 in 30,000 in Finland and G=
- reat Britain to 1 in 40,000 in the US, with a
- clustering of cases about 2-3 weeks after vaccination.=20
-
- An article in the Feb 28, 1998 Lancet (based on 12 cases) about a possible =
- association between inflammatory bowel disease,
- autism, and MMR vaccine (Wakefield et al) raised concerns that the vaccine =
- might increase the risk of autism. Wakefield and
- his colleagues did not claim to have actually shown that the vaccine caused=
- autism, but rather called for further investigation of
- the question. An accompanying editorial in the same issue of Lancet express=
- ed concerns about the validity of the study.=20
-
- The article, and the public concern it raised, led to several further inves=
- tigations of whether such an association existed. A
- research letter in the May 2, 1998 issue of Lancet reported on a 14-year pr=
- ospective study, in Finland, of children who had
- experienced gastrointestinal symptoms after receiving the MMR vaccine. 31 c=
- hildren (out of 3 million vaccine doses) reported
- gastrointestinal symptoms; all recovered, and none developed autism. A Work=
- ing Party on MMR Vaccine of the United
- Kingdom=92s Committee on Safety of Medicines (1999) examined hundreds of re=
- ports, collected by lawyers, of autism or
- Crohn's disease (a gastrointestinal disease) and similar problems, after th=
- e MMR vaccine, and concluded that there was no
- causal relationship. A Swedish study (Gillberg and Heijbel 1998) found no d=
- ifference in the prevalence of autism in children
- born before the introduction of MMR vaccine in Sweden, and children born af=
- ter. Wakefield and colleagues did laboratory
- assays in patients with inflammatory bowel disease (the mechanism which the=
- y had proposed for autism following the MMR
- vaccine), and found them negative for measles virus (Chadwick 1998, Duclos =
- 1998, cited by the CDC at
- http://www.cdc.gov/nip/vacsafe/vaccinesafety/sideeffects/autism.htm).=20
-
- Finally, a study in the June 12, 1999 issue of Lancet examined children bor=
- n with autism since 1979 in eight North Thames
- health districts, to look for changes in incidence or age at diagnosis sinc=
- e the introduction of MMR vaccination in the UK in
- 1988. The study found a steady increase in cases of autism, with no sudden =
- change in the trend after the introduction of the
- MMR vaccine. Parents most frequently reported first noticing symptoms of au=
- tism at around the age of 18 months, after the
- MMR vaccine would have been received, but there was no difference in age at=
- diagnosis between those vaccinated before and
- after 18 months and those never vaccinated. Developmental regression (which=
- occurred in about a third of the cases of autism)
- was not clustered in the months after vaccination.=20
-
- Q3c.6 What is mumps, and what are the risks of the disease?=20
-
- Mumps is a viral disease which is less contagious than measles or chicken p=
- ox. It causes swollen salivary glands. The most
- common complication is swelling of the testes (in about 20 percent of males=
- post puberty) and, less commonly, ovaries. Rarely,
- it can lead to sterility. Other complications are meningitis (less common t=
- han in measles) and acute pancreatitits. (A much longer
- list of complications can be found in the Merck Manual.)=20
-
- Q3c.7 How common was mumps before routine vaccination, and how common is it=
- now?=20
-
- 105,00 cases were reported in 1970; by 1990 the rate of reported cases was =
- down to 5,300.=20
-
- Q3c.8 How effective is the mumps vaccine?=20
-
- The Merck Manual estimates its effectiveness at 95%. The Physician's Desk R=
- eference gives its effectiveness as 96%.
- Switzerland has gotten lower efficacy rates, for mumps, out of its strain o=
- f the MMR vaccine, and Swiss scientists have been
- comparing the efficacy of different strains to improve this situation (Swis=
- s Medical Weekly,
- http://www.smw.ch/archive/1997/127-26-360-96.html and http://www.smw.ch/arc=
- hive/1998/128-17-351-98.html).=20
-
- Q3c.9 How long does the mumps vaccine last?=20
-
- The Merck Manual describes it as "durable." "Mumps immunization provides pr=
- otection through the blood serum antibodies for
- at least 12 years, and possibly much longer." (Pantell, Fries, and Vickery)=
- (See also Q3c.4 for the PDR's description of the
- duration of all the MMR-induced antibodies.)=20
-
- Q3c.10 What are some of the risks of the mumps vaccine?=20
-
- "Rarely, side effects of mumps vaccination have been reported, including en=
- cephalitis, seizures, nerve deafness, parotits,
- purpura, rash, and prurittis." (Merck. Encephalitis and convulsions were al=
- so on Merck's list of complications for mumps itself.)
- According to ACIP's 1996 report on vaccine adverse reactions, "Aseptic meni=
- ngitis has been epidemiologically associated
- with receipt of the vaccine containing the Urabe strain of mumps virus, but=
- not with the vaccine containing the Jeryl Lynn strain,
- the latter of which is used in vaccine distributed in the United States." [=
- MMWR 45(No. RR-12), 1996]=20
-
- Q3c.11 What is rubella, and what are the risks of the disease?=20
-
- Rubella is a mild illness, consisting of a mild fever and rash. Rare compli=
- cations include ear infections and encephalitis, but the
- real danger is to pregnant women. During the last rubella epidemic, in 1964=
- , 20,000 children were born with birth defects
- caused by rubella. Birth defects include deafness, cataracts, microcephaly,=
- and mental retardation. Children born with
- congenital rubella are als susceptible to rubella panencephalitis in their =
- early teens.=20
-
- Q3c.12 How common was rubella before routine vaccination, and how common is=
- it now?=20
-
- Before the development of the rubella vaccine, epidemics used to occur at i=
- rregular intervals in the spring, with major epidemics
- at 6 to 9 year intervals. (This means that one was just about due when the =
- vaccine came out in 1969.) There have been no
- major epidemics since 1969, but the number of cases of rubella and congenit=
- al rubella syndrome increased starting in 1989
- (Merck, also California Morbidity for November 19, 1993). (It was still a s=
- mall fraction of the pre-vaccine number, though,
- see table of disease frequencies in section 1.) "Serological surveys conduc=
- ted in the late 1970s and the 1980s indicated that 10
- to 25 percent of United States women of child-bearing age were shown to be =
- susceptible to rubella." (California Morbidity,
- November 19, 1993) It now appears to be declining again: "Following a resur=
- gence of rubella and congenital rubella syndrome
- (CRS) during 1989-1991, the reported number of rubella cases during 1992 an=
- d 1993 was the lowest ever recorded."
- (MMWR, cited in June 9, 1994 HICNet Medical News Digest.)=20
-
- Q3c.13 How effective is the rubella vaccine?=20
-
- The Merck Manual estimates its effectiveness at 95%. The Physician's Desk R=
- eference gives its effectiveness as 99%.=20
-
- Q3c.14 How long does the rubella vaccine last?=20
-
- The Merck Manual describes it as "sustained." (See also Q3c.4 for the PDR's=
- description of the duration of all the
- MMR-induced antibodies.)=20
-
- Another reference, from Heather Madrone:
-
- *************************************************************************
- D. M. Horstmann "Controlling Rubella: Problems and Perspectives"
- _Annals of Internal Medicine_, vol. 83, no. 3, pg. 412
-
- Horstmann found reduced antibody formation 3-5 years after administering
- the vaccine and 25% of those tested showed no immunity to rubella at
- all.
- *************************************************************************
-
- Q3c.15 What are the pros and cons of vaccinating all infants for rubella ve=
- rsus vaccinating females only at puberty?=20
-
- There is still some uncertainty about the most desirable rubella vaccinatio=
- n policy. In 1969, when the vaccine came out, it was
- decided to avert the expected epidemic by vaccinating all children over one=
- year, so that they would not spread rubella to their
- possible pregnant mothers - the first time one group of people was vaccinat=
- ed to avoid having them spread a disease to a
- different group of people. Supporters of this policy point out that the exp=
- ected epidemic didn't occur. The possible
- disadvantage is that we aren't sure how long the immunity lasts. Now that g=
- eneration of children is old enough to have children,
- and some of them may no longer be immune. In the past, 80% of the populatio=
- n was immune due to having had rubella in
- childhood.=20
-
- Some countries follow a policy of vaccinating girls at puberty if they don'=
- t have rubella antibodies (Pantell, Fries, and Vickery).
- The disadvantage is that vaccine side effects are more common at this age. =
- The most common is joint pain, which occurs in
- 10% of women who are vaccinated in adolescence or later. In some cases, it =
- has lasted as long as 24 months. (Pantell, Fries,
- and Vickery) The PDR describes this same side effect in somewhat milder ter=
- ms, saying that it generally does not last very long
- and "Even in older women (35-45 years), these reactions are generally well =
- tolerated and rarely interfere with normal
- activities." It does agree with Pantell, Fries, and Vickery that the incide=
- nce of this side effect increases with age: 0-3% of
- children and 12-20% of women have joint pain, and the pain is more marked a=
- nd of longer duration in the adult women. A few
- women (between 1 in 500 and 1 in 10,000) experience peripheral neuropathy (=
- tingling hands). Another risk of vaccinating later
- is the risk that a woman may be pregnant. So far, no connection with birth =
- defects has been demonstrated, but women are
- advised to avoid pregnancy for three months after getting the vaccination.=
- =20
-
- Current US policy is to vaccinate all children at 15 months, and give a boo=
- ster during school years. Adult women are advised
- to get an antibody test before becoming pregnant, and, if it comes up negat=
- ive, get vaccinated and wait three months before
- getting pregnant.=20
-
- There has not been a rubella epidemic since 1964, either in countries which=
- vaccinate all children at 15 months, or in countries
- which vaccinate girls only at puberty.=20
-
- Q3c.16 What are some of the risks of the rubella vaccine?=20
-
- The PDR has a long list of possible adverse reactions (besides arthritis an=
- d arthralgia, usually short-lived, see above). Most of
- them are either mild or rare.=20
-
- Q3c.17 When is the MMR vaccine contraindicated?=20
-
- People with an anaphylactic or anaphylactoid allergy to eggs or neomycin sh=
- ould not get the vaccine. Other allergies or chicken
- or feather allergies are not a contraindication. Vaccination should be defe=
- rred in case of fever. The PDR give active untreated
- tuberculosis as a contraindication, but the AHFS says that there is no evid=
- ence of a need to worry about TB. Both give immune
- deficiency as a contraindication (see PDR for a long list of immune deficie=
- ncies involved). Immune globulin preparation or
- blood/blood product received in the preceding 3 months. The same contraindi=
- cations apply individually to measles and mumps
- vaccines, but the rubella vaccine can be given by itself to people with an =
- anaphylactic egg allergy. The other contraindications
- still apply to the rubella vaccine alone. (California Morbidity, October 31=
- , 1987)=20
-
- Vaccine components capable of causing adverse reactions: for mumps and meas=
- les, chick fibroblast components; for mump,
- measles, and rubella, neomycin (Travel Medicine Advisor).=20
-
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D
- Section 3d. HiB (Hemophilus influenze B)
- [This section last updated September 19, 1999.]=20
-
- Q3d.1 What is hemophilus influenze B, and what are the risks of the disease=
- ?=20
-
- HiB is a bacteria which is one of the leading causes of meningitis in young=
- children. About 60% of cases are meningitis. The
- remaining 40% are cellulitis, epiglottis, pericarditis, pneumonia, sepsis, =
- and septic arthritis. Mortality rate can be about 5%, and
- there are neurologic sequelae in up to 38% of survivors.=20
-
- Q3d.2 How common was HiB before routine vaccination, and how common is it n=
- ow?=20
-
- Before routine vaccination, about 12,000 cases a year in the US, with a cum=
- ulative risk of 1 in 200 that a child would get the
- disease by age 5. A vaccine was introduced in 1985. Since the introduction =
- of the Hib conjugate vaccine in 1988, the
- race-adjusted incidence of Hib among children less than 5, has declined fro=
- m 41 cases per 100,000 in 1987 to two cases per
- 100,000 in 1993. (The incidence for people five or older remained stable. H=
- ib is most serious in children under 5.) (A decline
- of 95%, despite the fact that the National Health Interview Survey showed o=
- nly 67% of children 12-23 months had received at
- least one dose, and 36% three or more doses. This decline is attributed to =
- the elimination of carriage, which reduces Hib
- exposure even in unvaccinated children.) The CDC set a goal of eliminating =
- Hib in the US by 1996. (HICN708 Medical
- News, "[MMWR] Progress Elimination Haemophilus influenzae type b") As of Se=
- ptember 1999, this goal wasn't met, but
- there has been a significant decline; MMWR's "TABLE III. Provisional cases =
- of selected notifiable diseases preventable by
- vaccination, United States week ending September 11, 1999" records a cumula=
- tive total for 1998 of 788 cases, and for 1999
- of 820 cases, in the US.=20
-
- Q3d.3 How effective is the HiB vaccine?=20
-
- Estimates from different labs vary a lot. AHFS Drug Information, after noti=
- ng this variability, and the uncertainty as to what
- antibody level is adequate for protection, says that in one study, 75% of c=
- hildren 18-23 months and 85% of children 24-29
- months had serum anticapsular antibody levels of one microgram per millilit=
- er or greater. The PDR lists numerous studies, with
- results ranging from 100% efficacy to one study in which vaccinated childre=
- n had more cases of HiB than the unvaccinated
- group. With the exception of the latter study, all of the studies showed si=
- gnificant positive results, often with efficacy estimates
- over 90%.=20
-
- According to a NY Times article of 12/18/90, HiB vaccine produces lower ant=
- ibody response among Native Americans, but
- the new conjugated vaccine seems to produce higher antibody response in Nat=
- ive American children and may protect all
- children at a younger age.=20
-
- Q3d.4 How long does the HiB vaccine last?=20
-
- The duration of immunity is unknown. However, the disease is only dangerous=
- to very small children.=20
-
- Q3d.5 What are some of the risks of the HiB vaccine?=20
-
- In a study of 401 infants, fever occurred in 2%, and redness, warmth, or sw=
- elling in 3.3%. All adverse reactions were
- infrequent and transient. (PDR) The Institute of Medicine reported in 1994 =
- that evidence favored rejection of a causal
- relationship between early onset HiB disease and conjugate vaccines, but fa=
- vored acceptance of a causal relationship between
- early onset disease in children 18 months old or more whose first vaccinati=
- on was with unconjugated PRP vaccine. [MMWR
- 45(No. RR-12), 1996]=20
-
- Q3d.6 When is the HiB vaccine contraindicated?=20
-
- Hypersensitivity to any component of the vaccine, including diptheria toxoi=
- d and thimerosal in the multi-dose presentation.=20
-
- Vaccine components capable of causing adverse reactions: phenol, bacterial =
- polysaccharides, thimerosal (Travel Medicine
- Advisor).=20
-
- (Note: There is currently, as of 1999, a move toward replacing thimerosal i=
- n vaccines, so the reference to thimerosal here may
- shortly be out of date.)=20
-
- Q3d.7 What about rifampin prophylaxis?=20
-
- An alternative to HiB vaccination is rifampin prophylaxis, but it could be =
- unwieldy to administer. AHFS Drug Information says
- that it is "effective for eradicating nasopharyngeal carriage of HiB, but t=
- he efficacy of the drug for prevention of secondary
- disease has not been firmly established."=20
-
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
- =3D=3D=3D=3D
- Section 3e. Hepatitis B gamma globulin and hepatitis B vaccine
- [This section last updated on September 15, 1999.]=20
-
- Q3e.1 What is hepatitis B, and what are the risks of the disease?=20
-
- There are several forms of hepatitis, infections of the liver which cause j=
- aundice, nausea, and weakness. Hepatitis B is spread
- mainly by contact with infected blood and by intimate contact with bodily f=
- luids, such as in sexual intercourse and childbirth.
- However, the hepatitis B virus is far more resilient than, for example, the=
- AIDS virus, and the disease is not strictly a venereal
- disease, and can be caught even by people who are not sexually active. Hepa=
- titis B becomes chronic in 5-10% of those
- infected. Complications include hepatic necrosis, cirrhosis of the liver, c=
- hronic active hepatitis, and hepatocellular carcinoma.
- Hepatitis B is endemic throughout the world, and a serious problem in group=
- s at increased risk. Information about hepatitis B is
- available by calling 1-800-HEP-B-873. Another source of information about h=
- epatitis B and many other forms of liver disease
- is:=20
-
- American Liver Foundation
- 1425 Pompton Avenue
- Cedar Grove, NJ 07009
-
- A source on hepatitis B in particular is:=20
-
- Hepatitis B Coalition
- 1537 Selby Ave #229
- St Paul, MN 55104
- (612) 647-9009
-
- There is also a hepatitis mailing list, HEPV-L on LISTSERV@SJUVM.STJOHNS.ED=
- U. A Web page on Diseases of the
- Liver can be found at=20
-
- http://cpmcnet.columbia.edu/dept/gi/disliv.html=20
-
- A US government source of information on hepatitis is:=20
-
- Hepatitis Branch
- Mailstop G37
- CDC
- Atlanta, GA 30333
- or call the CDC Automated Voice Information System at (404) 332-255=
- 3.
-
- Hepatitis B should not be confused with hepatitis A, which is more contagio=
- us but less serious. Hepatitis A is spread through
- contaminated food and water. Symptoms can be mild flulike symptoms or sever=
- e nausea lasting for weeks. Hepatitis A does
- not become chronic and is rarely fatal. Other forms of hepatitis include he=
- patitis C, hepatitis D, and hepatitis E, and hepatitis
- (being a general term for inflammation of the liver) can also be caused by =
- certain medications. Information on other kinds of
- hepatitis can be obtained from the American Liver Foundation.=20
-
- Q3e.2 How common is hepatitis B?=20
-
- "The estimated lifetime risk of HBV infection in the United States varies f=
- rom almost 100% for the highest risk groups to
- approximately 5% for the population as a whole." (PDR) The CDC estimates ab=
- out 0.75 - 1 million chronic carriers in the US,
- and more than 170 million are estimated worldwide.=20
-
- Q3e.3 What is hepatitis B gamma globulin, and when is it given?=20
-
- It is given to people who have already been exposed to hepatitis B, to boos=
- t their immunity. In particular, it is given to children
- born to mothers with hepatitis B. It should be given as soon as possible af=
- ter birth for the best results.=20
-
- Q3e.4 How long does the immunity provided by hepatitis B gamma globulin las=
- t?=20
-
- Two months, maybe longer.=20
-
- Q3e.5 What are the risks and contraindications of hepatitis B gamma globuli=
- n?=20
-
- No known contraindications. A couple of diseases (see PDR for more informat=
- ion) are listed under precautions (a weaker
- form of warning than contraindication - in the case of precautions gamma gl=
- obulin may be given, but the extra risks of giving the
- gamma globulin have to be weighed against the benefits). These diseases, th=
- ough, aren't ones a newborn is likely to have, so
- they would probably not apply in the case of giving it to the newborn of a =
- mother infected with hepatitis B.=20
-
- Q3e.6 How effective is the hepatitis B vaccine?=20
-
- It varies depending on the age, sex, and general health of the recipient. A=
- bout 96-100% in infants and children 19 and under,
- 94-99% in adults 20-39, 88-91% in adults 40 or older. May be lower in men t=
- han women. Lower (only 64% in one study) in
- hemodialysis patients. (AHFS Drug Information 1992) The PDR estimated 95-96=
- % for infants, and agrees with AHFS about
- the conditions which reduce effectiveness.=20
-
- Q3e.7 How long does the hepatitis B vaccine last?=20
-
- There is evidence that immunity lasts up to ten years, but beyond that, the=
- duration is uncertain, and the need for booster doses
- not defined. (My source for the duration is Journal Watch, 9/1/93.)=20
-
- Q3e.8 What are some of the risks of the hepatitis B vaccine?=20
-
- Hepatitis B has traditionally been considered one of the safest and least r=
- eactogenic vaccines:=20
-
- "During clinical studies involving over 10,000 individuals distributed over=
- all age groups, no serious adverse reactions
- attributable to vaccine administration were reported." (PDR, 1993) The most=
- common adverse reactions were injection site
- soreness (22%) and fatigue (14%). A longer list of adverse reactions can be=
- found in the PDR. "Update: Vaccine Side Effects,
- Adverse Reactions, Contraindications, and Precautions," published by ACIP i=
- n 1996, reported that VAERS data showed a
- low rate of anaphylaxis (approximately one event per 600,000 doses given).=
- =20
-
- More recently, controversy has been aroused by news reports, particularly i=
- n France, of new or reactivated cases of multiple
- sclerosis, and other demyelinating disorders, within two to three months fo=
- llowing administration of hepatitis B vaccine. Critics
- argue that the risk is too high for a vaccine routinely given to children n=
- ot directly at much risk for hepatitis B. Supporters of
- vaccination argue that, given the demonstrated risk of liver cancer and cir=
- rhosis of the liver from hepatitis B, effective
- vaccination programs should not be abandoned for a hypothetical risk that t=
- he vaccine might in rare cases lead to multiple
- sclerosis and other demyelinating diseases.=20
-
- As is the case in other controversies about vaccination risks, part of the =
- difficulty is assessing just what effect the hepatitis B
- vaccine may have on demyelinating diseases. Multiple sclerosis is, in some =
- countries, the most common neurological disease of
- young adulthood. Though most commonly reported between 20 and 40, it can be=
- reported at younger and older ages, and,
- given near universal vaccination of pre-adolescents, some cases of MS are t=
- o be expected, simply by chance, in proximity to
- vaccination. Since the incidence of cases of multiple sclerosis attributed =
- to the vaccine, in France and elsewhere, is less than the
- number already expected for the age range in question, statistical analysis=
- is required, to determine whether the risk of MS and
- other demyelinating diseases is in fact higher in populations vaccinated fo=
- r hepatitis B, and, if so, what the risk might be.=20
-
- Several studies have been carried out, to date, to assess this risk, and mo=
- re are ongoing.=20
-
- ACIP reported, in 1996, that evidence was inadequate to establish or reject=
- a causal relationship between hepatitis B vaccine
- and demyelinating diseases of the central nervous system.=20
-
- The French National Drug Surveillance Committee studied people who received=
- more than 60 million doses of hepatitis B
- vaccine between 1989 and 1997, and found that the prevalence of neurologica=
- l disease, including MS, was actually lower in
- this group than in the general population.=20
-
- Three French studies, prompted by reports of MS, showed a slightly increase=
- d relative risk in the vaccinated population, but
- not one which was statistically significant. In response to this, the Frenc=
- h government required a risk-benefit analysis. The
- risk-benefit analysis did not attempt to determine whether the hepatitis B =
- vaccine in fact causes MS or other demyelinating
- diseases, but rather to use the largest possible risks which could be deriv=
- ed from the studies which had been done, and weigh
- these against the expected benefits of hepatitis B vaccine (with both being=
- assessed in a statistical, quantititive fashion). This
- study concluded that, though it isn't possible to determine yet whether the=
- re is an association between the hepatitis B vaccine
- and MS, the benefits of the vaccine for a given vaccinated pre-adolescent c=
- ohort would clearly outweigh the risks.=20
-
- In Canada, the Alberta Ministry of Health reported that a preliminary exami=
- nation of hospital admission data between 1975
- and 1995 suggests that the introduction of the hepatitis B vaccine in the m=
- id-1980s has not been marked by an increase in the
- incidence of multiple sclerosis.=20
-
- The World Health Organization Viral Hepatitis Prevention Board (VHPB) assem=
- bled experts, on September 28-30, 1998, to
- review the epidemiology and current understanding of MS. This group examine=
- d data on the epidemiology of hepatitis B, the
- epidemiology of multiple sclerosis, from national reporting systems in the =
- US, Italy, and Canada, from one active pediatric
- surveillance system in Canada, from industry post-marketing surveillance an=
- d clinical data, from published studies of hepatitis B
- safety, and from preliminary reports of a small number of unpublished epide=
- miological studies in the US, France, and the UK.
- They tried to decide between three hypotheses for explaining the relationsh=
- ip between the hepatitis B vaccine and MS: 1)
- coincidence, 2) "triggering," in which an illness which would have occurred=
- anyway was unmasked by the vaccine, or 3) a true
- causal relationship.=20
-
- Evidence for the hypothesis of coincidence included the lack of any statist=
- ically significant association with MS to date, and the
- fact that age and sex distributions of reported adverse events resemble age=
- and sex distributions seen before the vaccine.
- Evidence in support of an increased risk as precipitating factor was the fa=
- ct that some studies showed slightly increased risk of
- MS, though not to a statistically significant degree. Evidence against was =
- that another study showed no increased risk. The
- group concluded that the evidence for an association between the hepatitis =
- B vaccine and MS was weak, and did not meet the
- criterion for causality.=20
-
- Response to this data has shown a rare divergence in public health policies=
- . The French National Network of Public Health,
- while still recommending the vaccine as useful to pre-adolescents, conclude=
- d that, because of differences in individual risk for
- hepatitis B and for side effects of the vaccine and "the need for a medical=
- consultation including the personal and family history,"
- the vaccination program for pre-teens in the schools would be suspended. Th=
- is suspension was announced on October 1,
- 1998. Public health departments in several other countries, along with the =
- World Health Organization, criticized the French
- government for making a decision based more on politics than on the actual =
- risks, and reaffirmed existing vaccination policies.
- The US Congress held hearings on the subject, while the CDC affirmed that "=
- The scientific evidence to date does not support
- hepatitis B vaccination causing MS or other demyelinating diseases." (http:=
- //www.cdc.gov/nip/vacsafe/fs/qhepb.htm#7) Several
- organizations concerned with hepatitis B and multiple sclerosis, in the US =
- and Canada, came out with statements supporting
- continued hepatitis B vaccination.=20
-
- As I write this section of the FAQ, the CDC reports that at least six resea=
- rch projects are underway, in the US, France, and
- the UK, to examine what relationship, if any, exists between the hepatitis =
- B vaccine and multiple sclerosis. In the meantime,
- most countries are continuing to recommend universal hepatitis B vaccinatio=
- n for infants and for pre-teens who have not
- already been vaccinated.=20
-
- Q3e.9 When is the hepatitis B vaccine contraindicated?=20
-
- Sensitivity to yeast or any other component of the vaccine. Pregnancy is no=
- t a contraindication to hepatitis B vaccination. A
- previous anaphylactic response to the vaccine is a contraindication to furt=
- her doses.=20
-
- Vaccine components capable of causing adverse reactions: aluminum phosphate=
- , thimerosal, and formaldehyde (Travel
- Medicine Advisor). (Note, though, that as of September 1999, a thimerosal f=
- ree hepatitis B vaccine is available.)=20
-
- Q3e.10 Why did the ACIP and AAP change their recommendation about the hepat=
- itis B vaccine?=20
-
- Up until 1992, the recommendation was that hepatitis B vaccine be given onl=
- y to people in high risk groups for hepatitis B:
- people whose professions exposed them to blood, people at extra risk due to=
- their sexual practices or intravenous drug use,
- and certain populations (such as Southeast Asian immigrants) with a high in=
- cidence of the disease. The chief reason was cost; it
- was felt to be not cost-effective to vaccinate low-risk groups.=20
-
- Unfortunately, this policy was not successful in checking the spread of hep=
- atitis B. It proved difficult to identify high-risk
- people, and high-risk people did not volunteer in large numbers to be vacci=
- nated. For this reason, in 1992, the ACIP
- recommendation was switched to vaccination of teens and adults in high-risk=
- groups and universal vaccination of infants. The
- AAP made a similar recommendation but would also like to extend hepatitis B=
- vaccination to all adolescents, if possible.=20
-
- The American Liver Foundation also supports hepatitis B vaccination of infa=
- nts, and their pamphlet on the subject suggests a
- variety of ways in which even young children could come in contact with the=
- virus (through contact with blood, etc.). Though
- young children are at low risk of catching hepatitis B, their risk of devel=
- oping the chronic form of the disease if they do catch it
- is higher than for adults.=20
-
- The new policy was well-received internationally, and 30 countries now have=
- universal infant HBV vaccination programs.
- Many physicians remain skeptical, however, and a survey in North Carolina s=
- howed one third of pediatricians and <20% of
- family physicians supporting the new guidelines (Journal Watch, 9-1-93). (U=
- pdate: Journal Watch for Jan 15, 1995/Feb 7,
- 1995 reports that this vaccine is gaining physician acceptance, citing Arch=
- Pediatr Adolesc Med Sep 1994, p. 936)=20
-
- Why the resistance? One reason is a reluctance to give low-risk infants yet=
- another vaccination. Another is doubt about the
- duration of HBV vaccine. There is evidence that it lasts up to 10 years, bu=
- t we do not know yet whether it wears off beyond
- that point. There is concern that infants vaccinated for HBV may lose immun=
- ity during adolescence, when the risk of catching
- the disease is greatest. An alternative would be to vaccinate all children =
- at age 10 and give a booster at age 20. But compliance
- would likely be lower at age 10 than in infancy. Hepatitis B vaccine is adm=
- inistered in three shots over the course of six months,
- and it would be difficult to get preteens to all come in for the full serie=
- s. Also, 8% of hepatitis B infections occur before age 10,
- and the deadly form is three times greater in children (NY Times, 3/3/93:B8=
- ). Boosters could be given later to infants
- vaccinated for HBV if immunity proves to lapse.=20
-
- Hepatitis B vaccine is also often recommended for travel purposes.=20
-
- Q3e.11 Does vaccination for hepatitis B affect one's ability to donate bloo=
- d?=20
-
- *************************************************************************
- From=20Gregory Froehlich, MD (from a posting to sci.med):
-
- First, hepatitis B *antigen* is used to make Hep B vaccine. The
- antigen is grown in yeast culture; formerly, it was purified from the
- blood of people who were chronic hepatitis carriers. Antibodies are
- used in the gamma globulin shots used for hepatitis A or for passive
- immunization against hepatitis B if you're exposed.
-
- The local blood bank does not specifically test for exposure to
- hepatitis A (the kind you'd get from contaminated water). If a person
- has an active hep A infection, it will be picked up by elevated liver
- enzymes; if the person had such an infection in the past, it's over and
- done with--hep A doesn't give you a chronic, subclinical infection.
- Antibodies to hepatitis A should not preclude blood donation.
-
- They check for chronic hep B carriers by testing for hep B surface
- antigen. They test for recent hep B infection by testing for hep B
- core antibody. This antibody does not carry disease, but rather
- indicates that the person was recently infected and might or might not
- still be infectious. They do not test for surface *antibody*, which
- would indicate either (a) former hep B infection which was cleared, or
- (b) immunization against hep B--in either case, not infectious. I've
- got hep B surface antibody, because I was immunized; I can still donate
- blood.
-
- Blood banks also test for hepatitis C antibody; people with this
- antibody can still be infectious.
- *************************************************************************
-
- Q3e.12 Do people who have showed up positive on the blood banks' tests for =
- hepatitis B exposure still need to be
- vaccinated?=20
-
- It is still useful to be vaccinated, because some of the people who show up=
- positive on the blood bank tests are false positive.=20
-
- Q3e.13 I will be travelling to an area where hepatitis B shots are recommen=
- ded, but I have less than six months before I leave.
- Is there an accelerated schedule for hepatitis B vaccination?=20
-
- _Travel Medicine Advisor_ lists an accelerated schedule, with 3 doses at 0,=
- 30, and 60 days. With this schedule, a fourth dose
- is recommended at 12 months if there is still a risk for hepatitis B exposu=
- re.=20
-
-