High rates of SARS-CoV-2 infection in pregnant Ugandan women and association with stunting in infancy

Background SARS-CoV-2 has been well studied in resource-rich areas but many questions remain about effects of infection in African populations, particularly in vulnerable groups such as pregnant women. Methods We describe SARS-CoV-2 immunoglobulin (Ig) G and IgM antibody responses and clinical outcomes in mother-infant dyads enrolled in malaria chemoprevention trials in Uganda. Results From December 2020 to February 2022, among 400 unvaccinated pregnant women, serologic assessments revealed that 128 (32%) were seronegative for anti-SARS-CoV-2 IgG and IgM at enrollment and delivery, 80 (20%) were infected either prior to or early in pregnancy, and 192 (48%) were infected or re-infected with SARS-CoV-2 during pregnancy. We observed preferential binding of plasma IgG to Wuhan-Hu-1-like antigens in individuals seroconverting up to early 2021, and to Delta variant antigens in a subset of individuals in mid-2021. Breadth of IgG binding to all variants improved over time. No participants experienced severe respiratory illness during the study. SARS-CoV-2 infection in early pregnancy was associated with lower median length-for-age Z-score at age 3 months compared with no infection or late pregnancy infection (- 1.54 versus −0.37 and −0.51, p=0.009). Conclusion Pregnant Ugandan women experienced high levels of SARS-CoV-2 infection without severe respiratory illness. Variant-specific serology testing demonstrated evidence of antibody affinity maturation at the population level. Early gestational SARS-CoV-2 infection was associated with shorter stature in early infancy. Funding This work was supported by: Stanford MCHRI/Stephen Bechtel Endowed Fellowship in Pediatric Translational Medicine (KJ), Swiss National Science Foundation PRIMA grant PR00P3_208580 (KR), the Bill and Melinda Gates Foundation, and NIAID (T32-AI052073, U01- AI141308, U01-AI155325).