Pneumococcal nasopharyngeal carriage among infants born to human immunodeficiency virus-infected mothers immunized with pneumococcal polysaccharide vaccine during gestation.

BACKGROUND: We have previously shown that 23-valent pneumococcal polysaccharide vaccine (PPV) is immunogenic in human immunodeficiency virus (HIV)-infected mothers and provides vaccine-induced antibodies to the infant. We compared the nasopharyngeal pneumococcal colonization (NPC) rates in <6-month-old infants born to HIV-infected mothers, according to immunization with PPV during pregnancy.
METHODS: NPC was evaluated in 45 term infants born to vaccinated women (PPV+) and in 60 infants in a control group (PPV-), at 2 months (±30 days), 4 months (±30 days), and 6 months (±30 days) of age.
RESULTS: A total of 82 infants completed the study (at least 2 of 3 evaluations), 35 (77%) in the PPV+ and 47 (78.3%) in the PPV- groups, respectively. Infant gender, HIV infection status, number of adults, children, and smokers in the household, day-care attendance, occurrence of respiratory signs, and cotrimoxazole use were similar in both groups. NPC rates increased equally with age in both groups (2 months = 26.7% vs. 25.6%; 4 months = 34.5% vs. 38.6%; 6 months = 38.7% vs. 56.3%, in PPV+ and PPV-, respectively). After controlling for potential confounders, we found no association between maternal vaccination and infant pneumococcal carriage (adjusted odds ratio = 0.70; 95% confidence interval: 0.23, 2.21)
CONCLUSIONS: Vaccination of HIV-infected mothers with PPV did not protect infants younger than 6 months of age from nasopharyngeal pneumococcal carriage.