Measles vaccination and HIV infection

Credit: WHO / Christopher Black

Measles in children with HIV infection is more often severe and results in higher mortality. Infants born to HIV-infected mothers are at higher risk for measles from 9 months of age.

Measles vaccines, a live attenuated vaccine, are among the most safe and effective vaccines. They should be given routinely to potentially susceptible, asymptomatic, HIV-infected children, adolescents and young adults. Only those with severe clinical symptoms of HIV infection are contraindicated for vaccination. These people often do not develop a protective immune response and are at increased risk of severe complications.

Given the high risk of measles at 9 months of age, WHO recommends that infants infected with HIV receive an early dose of measles vaccine at 6 months of age, followed by a routine dose at 9 months (or according to the routine immunization schedule). Earlier age of vaccination is recommended because HIV-infected infants exhibit a better seroconversion rate at 6 months than at 9 months of age, possibly because of increasing HIV-associated immunodeficiency with age.

HIV-infected infants vaccinated at 6 and 9 months should receive a third measles vaccination (or second opportunity) to prevent the proportion of unprotected children in the population from reaching dangerous levels. Recent studies suggest waning immunity among HIV-infected children, making this recommendation especially important in regions with high HIV prevalence.31