Background: HIV infection can have important although sometimes unexpected consequences, such as contributing to enlargement of the pool of rubella-susceptible children.
Methods: At the Federal University of São Paulo, Brazil, we assessed response to rubella immunization at 15 months of age in 15 human immunodeficiency virus type 1 (HIV)-infected children, 20 seroreverted children (SR) and 18 healthy control children born to HIV-seronegative mothers (CON). Blood samples were collected before and 3 months after vaccination. All HIV-infected children had started highly active antiretroviral therapy during their first 6 months of life. Serum samples were tested with a rubella IgG enzyme-linked immunosorbent assay kit.
Results: HIV children in immunologic categories 2/3 had lower rubella antibody titers (geometric mean, 33 IU/mL) than those from CON (125 IU/mL) and SR group (236 IU/mL) (Tukey, P = 0.01). Antibody values after vaccination were positively associated with CD4 T cell numbers and negatively associated with HIV viral load assessed immediately before vaccination. The percentage of children with protective antibodies after vaccination (above 10.0 IU/mL) was also significantly different among groups (Fisher's exact test, P = 0.013): CON, 94%; SR, 100%; HIV category 1, 100%; HIV category 2/3, 62%.
Conclusions: HIV-infected children with a preserved immune system at measles-mumps-rubella immunization can have a good response to rubella vaccine. In contrast, those in more advanced categories for HIV infection respond poorly.
From the Department of Pediatrics, Federal University of Sao Paulo, Sao Paulo, Brazil
Accepted for publication February 19, 2004.
Supported by Fundaçao de Amparo à Pesquisa do Estado de Sao Paulo, Brazil (grants 97/06118-8 and 97/10422-5).
Reprints not available.