Characterization of Functional Antibody and Memory B-Cell Responses to pH1N1 Monovalent Vaccine in HIV-Infected Children and Youth

ObjectivesWe investigated immune determinants of antibody responses and B-cell memory to pH1N1 vaccine in HIV-infected children.MethodsNinety subjects 4 to ResultsAt entry, 26 (29%) subjects had pH1N1 protective HAI titers (≥1:40). pH1N1-specific HAI, neutralizing titers, AI, IgG ASC, IL-2 and IL-4 increased in response to vaccination (pConclusionsHIV-infected children on HAART mount a broad B-cell memory response to pH1N1 vaccine, which was higher for subjects with baseline HAI≥1:40 and increased with age, presumably due to prior exposure to pH1N1 or to other influenza vaccination/infection. The response to the vaccine was dependent on B-cell subset distribution, but not on CD4 counts or viral load.Trial RegistrationClinicalTrials.gov NCT00992836