This 640 x 207 pixel image depicts that the speed at which HIV levels rise (linear plots) over the years may depend greatly on the composition of the initial immune response (insets). Modeling suggests that if the immune attack directed against conserved epitopes (ones found on every viral particle) can limit viral growth on its own (left), the body might keep viral levels low indefinitely--even after the response to readily changeable epitopes inevitably decays. This pattern is uncommon. If the combined responses are weak (center), viral levels will rise quickly. If the combined responses are strong but the "conserved" response cannot by itself control the virus (right), the typical, fairly slow course of viral multiplication should result. In that situation, levels will begin to soar when the ability to respond efficiently to changeable epitopes is lost.
