Long-term Durability of Responses to 2 or 3 Doses of Hepatitis A Vaccination in Human Immunodeficiency Virus-Positive Adults on Antiretroviral Therapy.

Abstract

Previous studies have shown that the durability of serological response is impaired in successfully vaccinated human immunodeficiency virus-1 (HIV-1) positive subjects after receiving 2 doses of inactivated hepatitis A virus (HAV) vaccine. We evaluated whether 3 doses compared with 2 doses of HAV vaccine could improve the long-term seroprotection for this susceptible group. Antibody persistence among HIV-positive men who have sex with men aged 18-40 years who had received 2 or 3 doses of HAV vaccine according to a 0-6- or a 0-1-6-month schedule was evaluated biannually for 5 consecutive years in this prospective, nonrandomized cohort study. At the end of 5 years, seroprotection persisted in 79% (146/185) versus 76% (85/110) and 94% (146/155) versus 88% (84/95) of the 3- versus 2-dose primary responders by intention-to-treat and per-protocol analyses, respectively (P > .05). Throughout the 5 years, the geometric mean concentrations of anti-HAV immunoglobulin G (IgG) were significantly higher for the 3-dose than the 2-dose group. In the multivariable analysis, a 3-dose regimen compared with a 2-dose regimen (odds ratio = 3.36; 95% confidence interval = 1.14-9.93) was independently associated with sustained seroprotection. Three doses versus 2 doses of HAV vaccine improve the durability of immune responses in terms of higher concentrations of specific IgG, which take longer to decay to subthreshold levels.