Maternal HIV infection and antibody responses against vaccine-preventable diseases in uninfected infants.

CONTEXT

Altered immune responses might contribute to the high morbidity and mortality observed in human immunodeficiency virus (HIV)-exposed uninfected infants.

OBJECTIVE

To study the association of maternal HIV infection with maternal- and infant-specific antibody levels to Haemophilus influenzae type b (Hib), pneumococcus, Bordetella pertussis antigens, tetanus toxoid, and hepatitis B surface antigen.

DESIGN, SETTING, AND PARTICIPANTS: A community-based cohort study in Khayelitsha, Western Cape Province, South Africa, between March 3, 2009, and April 28, 2010, of 109 HIV-infected and uninfected women and their infants. Serum samples from 104 women and 100 infants were collected at birth and samples from 93 infants were collected at 16 weeks.

MAIN OUTCOME MEASURE

Level of specific antibody in mother-infant pairs at delivery and in infants at 16 weeks, determined by enzyme-linked immunosorbent assays.

RESULTS

At birth, HIV-exposed uninfected infants (n = 46) had lower levels of specific antibodies than unexposed infants (n = 54) did to Hib (0.37 [interquartile range {IQR}, 0.22-0.67] mg/L vs 1.02 [IQR, 0.34-3.79] mg/L; P < .001), pertussis (16.07 [IQR, 8.87-30.43] Food and Drug Administration [FDA] U/mL vs 36.11 [IQR, 20.41-76.28] FDA U/mL; P < .001), pneumococcus (17.24 [IQR, 11.33-40.25] mg/L vs 31.97 [IQR, 18.58-61.80] mg/L; P = .02), and tetanus (0.08 [IQR, 0.03-0.39] IU/mL vs 0.24 [IQR, 0.08-0.92] IU/mL; P = .006). Compared with HIV-uninfected women (n = 58), HIV-infected women (n = 46) had lower specific antibody levels to Hib (0.67 [IQR, 0.16-1.54] mg/L vs 1.34 [IQR, 0.15-4.82] mg/L; P = .009) and pneumococcus (33.47 [IQR, 4.03-69.43] mg/L vs 50.84 [IQR, 7.40-118.00] mg/L; P = .03); however, no differences were observed for antipertussis or antitetanus antibodies. HIV-exposed uninfected infants (n = 38) compared with HIV-unexposed infants (n = 55) had robust antibody responses following vaccination, with higher antibody responses to pertussis (270.1 [IQR, 84.4-355.0] FDA U/mL vs 91.7 [IQR, 27.9-168.4] FDA U/mL; P = .006) and pneumococcus (47.32 [IQR, 32.56-77.80] mg/L vs 14.77 [IQR, 11.06-41.08] mg/L; P = .001).

CONCLUSION

Among South African infants, antenatal HIV exposure was associated with lower specific antibody responses in exposed uninfected infants compared with unexposed infants at birth, but with robust responses following routine vaccination.