Immunogenicity, immunologic memory, and safety following measles revaccination in HIV-infected children receiving highly active antiretroviral therapy

Background. Response rates and immunologic memory following measles vaccination are reduced in human immunodeficiency virus (HIV)-infected children in the absence of highly active antiretroviral therapy (HAART). Methods. HIV-infected children 2 to <19 years old receiving HAART and with HIV loads <30 000 copies/ mL, CD4% ≥15, and ≥1 prior measles-mumps-rubella vaccination (MMR) were given another MMR. Measles antibody concentrations before and 8, 32, and 80 weeks postvaccination were determined by plaque reduction neutralization (PRN). A subset was given another MMR 4-5 years later, and PRN antibody was measured before and 7 and 28 days later. Results. At entry, 52% of 193 subjects were seroprotected (PRN ≥120 mIU/mL). Seroprotection increased to 89% 8 weeks postvaccination, and remained at 80% 80 weeks postvaccination. Of 65 subjects revaccinated 4-5 years later, 85% demonstrated memory based on seroprotection before or 7 days after vaccination. HIV load ≤400 copies/mL at initial study vaccination was associated with higher seroprotection rates, greater antibody concentrations, and memory. Grade 3 fever or fatigue occurred in 2% of subjects. Conclusions. Measles revaccination induced high rates of seroprotection and memory in children receiving HAART. Both endpoints were associated with HIV viral load suppression.