Safely and immunogenicity of an inactivated hepatitis A vaccine among HIV-infected subjects

Background. Hepatitis A is a major health risk for many human immunodeficiency virus (HIV)-infected individuals. Vaccination is a potentially attractive measure to reduce the incidence of hepatitis A among this population, but data on its safety and immunogenicity are incomplete. Methods. Ninety HIV-uninfected adults received an inactivated hepatitis A vaccine (VAQTA; Merck), and 90 HIV-infected subjects were randomized, in double-blind fashion, to receive either the vaccine or placebo. The HIV-infected subjects were stratified by CD4 cell count, with 45 subjects having CD4 cell counts of ≥300 cells/ mm3 and 45 subjects having CD4 cell counts of <300 cells/mm3. Vaccine was given at weeks O and 24 of the study. Results. Seroconversion rates at week 28 of the study were 94% among the HIV-infected subjects and 100% among the HIV-uninfected control subjects. HIV-infected subjects with CD4 cell counts of <300 cells/mm3 had a seroconversion rate of 87%, and HIV-infected subjects with CD4 cell counts of ≥300 cells/mm3 had a seroconversion rate of 100%. The vaccine was generally well tolerated, and no adverse effect on either HIV load or CD4 cell count was found. Conclusion. Hepatitis A vaccine was both immunogenic and safe among HIV-infected subjects.