Immune Response to Influenza Vaccine in HIV-Infected Individuals

The purpose of this protocol is to evaluate the effect of HIV viral load and CD4 counts on the generation of influenza-specific antibodies and influenza-specific B cell responses in HIV-infected adults. HIV-infected subjects will be enrolled to receive the influenza vaccine appropriate to the on-going USA influenza season (Oct-March). Laboratory studies (including influenza titers, influenza-specific B cell frequencies, CD4 counts, and HIV viral loads) will be obtained at baseline (day of vaccination), day 7, 28, and 54 post-vaccination. HIV-negative healthy volunteers will serve as controls. Although there are some risks to influenza vaccine, the CDC Advisory Committee on Immunizations recommends influenza vaccination for HIV-infected patients. The primary study risks are those of phlebotomy and the inconvenience of multiple visits. Subjects will be compensated for participation in the study. Total enrollment of the study is a maximum of 165 subjects (132 HIV-infected individuals and 33 HIV-negative controls).