Immunogenicity and Immunologic Memory after Hepatitis B Virus Booster Vaccination in HIV-Infected Children Receiving Highly Active Antiretroviral Therapy

Hepatitis B virus (HBV) is an important cause of comorbidity in individuals infected with human immunodeficiency virus (HIV). High rates of HBV infection among HIV-infected adolescents and young adults are documented [1]. Coinfection is associated with greater HBV replication and viremia, persistence of hepatitis B surface antigen, and higher rates of chronic carriage, superinfection, reactivation, transmission, and chronic active hepatitis, cirrhosis, and death [2–4]. Therefore, there is a need to protect HIV-infected populations against HBV. Many studies have indicated that seroconversion rates after HBV vaccination are low among children (12%–78%) and among adolescents and adults (18%–56%) infected with HIV, compared with rates of >90% among HIV-uninfected populations [1–16]. Although some studies have suggested that seroconversion rates are improved among HIV-infected adults treated with highly active antiretroviral therapy (HAART), they remain in the range of 32%–59% [2–4, 16]. The effect that HAART has on the response to HBV vaccine among children has not been sufficiently studied. P1024 is a multicenter study of the International Maternal Pediatric Adolescent AIDS Clinical Trials Group (IMPAACT) designed to evaluate immunogenicity and safety of vaccines in HIV-infected children receiving HAART, and P1061s is a substudy that evaluated immunologic memory after vaccination in P1024. The present report focuses on immunogenicity, safety, and memory responses associated with HBV vaccination.