Effect of HIV and Malaria in Pregnancy on Pertussis-specific Antibodies and Transplacental Antibody Transfer: A Secondary Analysis of a Prospective Cohort Study in Mozambican Pregnant Women and Their Infants.

BACKGROUND

Infection during pregnancy may affect maternal and infant immunity against childhood diseases. We aimed to evaluate the effects of maternal HIV and malaria on maternal and infant pertussis immunity and placental antibody transfer.

METHODS

A prospective study was conducted in mother-infant pairs in Mozambique. Peripheral and cord blood samples were collected for pertussis-specific immune assays. Maternal HIV serostatus and Plasmodium falciparum infection were assessed. The placental transfer was assessed using cord-to-mother ratios of IgG against pertussis toxin (PT), pertactin (PRN) and fimbriae 2/3 (FIM).

RESULTS

A total of 270 mother-infant pairs were included: 99 mothers with HIV and 40 mothers with malaria. Pregnant women with HIV showed a reduction in placental transfer [PT: 12.7%, 95% confidence interval (CI): 2.6-21.7, P = 0.015; PRN: 14.6%, 95% CI: 6.3-22.1, P = 0.001; and FIM: 7.5%, 95% CI: -6.6 to 19.7, P = 0.282] compared with women without HIV. A trend toward reduction in IgG transfer was observed among women with malaria (PT: 9.5%, 95% CI: -4.2 to 21.4, P = 0.165; PRN: 5.0%, 95% CI: -7.0 to 15.7, P = 0.394; and FIM: 15.9%, 95% CI: -0.9 to 30.0, P = 0.062) compared with those without. Maternal HIV infection (odds ratio: 4.43, 95% CI: 2.14-9.1; P < 0.001) and high viral load (odds ratio: 4.37, 95% CI: 1.4-12.2; P = 0.033) were associated with impaired placental transfer.

CONCLUSIONS

Maternal HIV infection is associated with lower mother-to-infant transfer of pertussis antibodies. While efforts continue in the health care of pregnant women with HIV, interventions such as maternal immunization can be a valuable strategy to prevent pertussis in infants.