Pneumococcal Vaccine and Routine Pediatric Immunizations in HIV-Infected Children Receiving Anti-HIV Drugs

Overview

The purpose of this study is to determine if 2 doses of Pneumococcal Conjugate Vaccine (PCV) followed by 1 dose of Pneumococcal Polysaccharide Vaccine (PPV) in HIV-infected children on anti-HIV therapy is helpful and safe in fighting pneumococcal infections in this group of children. This study will also look at the protection provided by childhood vaccination against measles, pertussis, and hepatitis B virus. Pneumococcal infections are the most common AIDS-related infection in HIV-infected children. PCV may help reduce the chances of HIV-infected children getting pneumococcal infections. This study will look at whether pneumococcal vaccines are safe and effective in HIV-infected children receiving HAART. It will look at whether HIV-infected children are protected by childhood vaccines received previously and if more doses are safe and improve protection.

Infection by Streptococcus pneumoniae is the most frequent opportunistic infection observed in HIV-infected children. PCVs are immunogenic and efficacious in normal children and offer hope of reducing pneumococcal infections in HIV-infected children. The degree to which children on HAART are protected by prior immunizations and are responsive to new immunizations is still largely undefined. This study is designed to answer whether PCV immunizations are safe and effective. The immune responses to prior immunizations and responsiveness to booster doses of vaccines against measles, pertussis, and hepatitis B virus of children on HAART will also be examined. Answers to these questions will determine whether these children are likely to be protected against these clinically relevant pathogens and whether they should routinely receive booster doses of these vaccines after a period of HAART. Patients are stratified on the basis of CD4 percentage and age. Patients that previously received a primary hepatitis B vaccine (HBV) series receive an HBV immunization at entry. Other vaccinations may be given (based on age and/or CD4 cell measurement, and immunization status) for PCV at entry and 2 months, and measles-mumps-rubella (MMR) vaccine and PPV at 4 months. Some patients may be administered DTaP at a 6-month visit on the basis of age, previous immunization history, and negative tetanus antibody status. Follow-up visits are done at 8, 12, and 24 months. Blood samples are collected at all clinic visits for assessment of HIV RNA, immune responses against pneumococcus, measles, pertussis, and hepatitis B virus, as well as for laboratory evaluations.