MEASLES VACCINE, HIV INFECTION, AND ANTIRETROVIRAL THERAPY—A WINDOW OF OPPORTUNITY

Tuesday, 28th of January 2014

[source]Journal of Infectious Diseases[|source]

Early in the human immunodeficiency virus (HIV) epidemic, it was recognized that measles can cause severe disease in HIV-infected children. Prior to highly active antiretroviral therapy (HAART), HIV-infected children had reduced response rates, lower antibody titers, and more rapid antibody decline following measles vaccination; lack of recall responses; and vaccine failures. Endemic measles and measles outbreaks pose a risk to HIV-infected children, and the HIV epidemic may complicate efforts for global measles elimination. Therefore, it becomes important to assess vaccine-induced immunity against measles in HIV-infected children in the context of HAART.

In a multi-country study, the International Maternal Pediatric Adolescent AIDS Clinical Trials Group evaluated immunogenicity of vaccines in HIV-infected children on HAART and a sub-study evaluated immunologic memory following vaccination. This report focuses on immunogenicity, safety, and immunologic memory associated with measles vaccination. More details are available at:  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3491735/

Abstract

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.