780 Measles and Rubella Antibodies in Fully Immunized HIV-1 Infected Children: Response to an Extra MMR Dose under HAART D. Takano*, P. Russo, A. Rufino, R. Succi, L. Weckx, M. Isabel de Moraes-Pinto Fed Univ of Sao Paulo, Brazil
Background: HIV-1 infected children have a poor response to immunization. However, few studies have assessed that population under HAART.
Methods: Seventy (70) HIV-1-infected children (HIV group, mean age: 73 months [mos]) and 69 healthy HIV-seronegative children (CNT group, mean age: 69 mos) were assessed for measles and rubella IgG antibodies at the Pediatric AIDS Clinic of the Federal Univ of Sao Paulo, Brazil. All children had been previously immunized with at least 1 MMR vaccine after 12 mos of age. Antibodies were tested by indirect ELISA. Children with measles antibodies < 0.2IU/mL and/or rubella antibodies < 16IU/mL received an extra MMR vaccine and had blood samples collected before and 1-3 mos after the procedure.
Results: Mean measles and rubella antibodies from HIV group were significantly lower than those from CTN group (measles:1.2 x 1.6 IU/mL; rubella: 63.0 x 103.6 IU/mL; t-test, p < 0.001 for both antigens). Whereas only 31% of HIV children had protective antibody levels for measles and rubella, 85% of CNT children were immune to both diseases. No correlation was found between antibody levels and number of previous MMR doses, time interval since last dose or clinical category for HIV infection. However, HIV children from immunologic categories 2 and 3 were the ones with lower measles and rubella antibody levels when compared to CNT group (Tukey, p = 0.05); HIV children from immunologic category 1 had similar measles and rubella antibody levels to CNT children. Fourteen (14) of the 48 children without protective measles and/or rubella antibody levels could receive an extra MMR vaccine because they did not belong to advanced clinical or immunologic categories for HIV infection. Among the 12 children who were assessed for that procedure, all were under HAART. Only 1 maintained measles and rubella antibodies below protective levels. Mean measles and rubella antibodies attained after the extra dose in HIV group (0.9 and 81.4 IU/mL, respectively) were significantly higher than pre-booster levels (0.3 and 24.9 IU/mL, respectively) (paired t-test, p < 0.001 for both antigens).
Conclusions: Although fully immunized, HIV-infected children have lower measles and rubella antibodies than healthy uninfected children. However, those without evidence of immunosuppression have higher antibody levels, similar to the general population. For those who need and can receive life virus vaccines, an extra MMR dose leads to an immediate good antibody response.
