[Search of antimeasles antibodies in HIV-infected children after basic immunization]

OBJECTIVE: To determine the presence of antimeasles antibodies in children perinatally infected with HIV and properly immunized. METHODS: A retrospective cohort study conducted in Belo Horizonte by the Universidade Federal de Minas Gerais, between 1995 and 1996. Twenty one children perinatally infected with HIV and 29 immunocompetent noninfected children were included in the study. Information about measles vaccination was obtained from patientś immunization charts. The presence of neutralizing antibodies against the measles was determined by the plaque reduction neutralization test and IgM was measured by ELISA. The level of significance was set at 5% in all the performed statistical analyses. RESULTS: Median age was 44.5 months for HIV-infected patients and 62.0 months for noninfected children (P=0.64). Both groups received on average two doses of antimeasles vaccine. All HIV-seronegative patients presented antimeasles antibody titers greater than 50 mIU/ml, whereas 57.1% of infected children presented titers above this value (P=0.0001). The geometric mean titer of neutralizing antibodies was significantly lower in the group of HIV-infected children (433.5 mIU/ml) than in noninfected children (1,668.1 mIU/ml), P=0.001. All patients in both groups were negative for antimeasles IgM. CONCLUSION: In the present study, HIV-infected children showed a lower seroprevalence of antimeasles antibody after immunization than noninfected children. These results emphasize the risk of acquisition of measles virus and the need to evaluate alternatives to the vaccination of HIV-infected children in an attempt to maximize the protection against the measles in this group of patients.