Long-term durability of immune responses after hepatitis A vaccination among HIV-infected adults

Abstract

Background. Vaccination provides long-term immunity to hepatitis A virus (HAV) among the general population, but there are no such data regarding vaccine durability among human immunodeficiency virus (HIV) - infected adults. Methods. We retrospectively studied HIV-infected adults who had received 2 doses of HAV vaccine. We analyzed blood specimens taken at 1 year, 3 years, and, when available, 6-10 years postvaccination. HAV immunoglobulin G (IgG) values of ≥10 mIU/mL were considered seropositive. Results. We evaluated specimens from 130 HIV-infected adults with a median age of 35 years and a median CD4 cell count of 461 cells/mm3 at or before time of vaccination. Of these, 49% had an HIV RNA load <1000 copies/mL. Initial vaccine responses were achieved in 89% of HIV-infected adults (95% confidence interval [CI], 83%-94%), compared with 100% (95% CI, 99%-100%) of historical HIV-uninfected adults. Among initial HIV-infected responders with available specimens, 90% (104 of 116; 95% CI, 83%-95%) remained seropositive at 3 years and 85% (63 of 74; 95% CI, 75%-92%) at 6-10 years. Geometric mean concentrations (GMCs) among HIV-infected adults were 154, 111, and 64 mIU/mL at 1, 3, and 6-10 years, respectively, compared with 1734, 687, and 684 mIU/mL among HIV-uninfected persons. Higher GMCs over time among HIV-infected adults were associated with lower log10 HIV RNA levels (β = 2.12, P = .04). Conclusions. Most adults with well-controlled HIV infections had durable seropositive responses up to 6-10 years after HAV vaccination. Suppressed HIV RNA levels are associated with durable HAV responses. © The Author 2011. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved.