Background HIV may increase SARS-CoV-2 infection risk and COVID-19 severity generally, but data are limited about its impact on postpartum women and their infants. As such, we characterized SARS-CoV-2 infection among mother-infant pairs in Nairobi, Kenya. Methods We conducted a nested study of 62 HIV-uninfected and 64 healthy women living with HIV, as well as their HIV-exposed uninfected (N = 61) and HIV-unexposed (N = 64) infants, participating in a prospective cohort. SARS-CoV-2 serology was performed on plasma collected between May 1, 2020-February 1, 2022 to determine the incidence, risk factors, and symptoms of infection. SARS-CoV-2 RNA PCR and sequencing was also performed on available stool samples from seropositive participants. Results SARS-CoV-2 seropositivity was found in 66% of the 126 mothers and in 44% of the 125 infants. There was no significant association between SARS-CoV-2 infection and maternal HIV (Hazard Ratio [HR] = 0.810, 95% CI: 0.517–1.27) or infant HIV exposure (HR = 1.47, 95% CI: 0.859–2.53). Maternal SARS-CoV-2 was associated with a two-fold increased risk of infant infection (HR = 2.31, 95% CI: 1.08–4.94). Few participants (13% mothers, 33% infants) had symptoms; no participant experienced severe COVID-19 or death. Seroreversion occurred in about half of mothers and infants. SARS-CoV-2 sequences obtained from stool were related to contemporaneously circulating variants. Conclusions These data indicate that postpartum Kenyan women and their infants were at high risk for SARS-CoV-2 infection and that antibody responses waned over an average of 8–10 months. However, most cases were asymptomatic and healthy women living with HIV did not have a substantially increased risk of infection or severe COVID-19.

Background: HIV may increase SARS-CoV-2 infection risk and COVID-19 severity generally, but data are limited about its impact on postpartum women and their infants. As such, we characterized SARS-CoV-2 infection among mother-infant pairs in Nairobi, Kenya. Methods: We conducted a nested study of 53 HIV-uninfected and 51 healthy women living with HIV, as well as their HIV-exposed uninfected (N=41) and HIV-unexposed (N=48) infants, participating in a prospective cohort. SARS-CoV-2 serology was performed on plasma collected between 1 May-31 December 2020 to determine the incidence, risk factors, and symptoms of infection. SARS-CoV-2 RNA PCR and sequencing was also performed on stool samples from seropositive participants. Results: SARS-CoV-2 seropositivity was found in 38% of the 104 mothers and in 17% of the 89 infants. There was no significant association between SARS-CoV-2 infection and maternal HIV (Hazard Ratio [HR]=1.51, 95% CI: 0.780-2.94) or infant HIV exposure (HR=1.48, 95% CI: 0.537-4.09). Maternal SARS-CoV-2 was associated with a >10-fold increased risk of infant infection (HR=10.3, 95% CI: 2.89-36.8). Twenty percent of participants had symptoms, but no participant experienced severe COVID-19 or death. Seroreversion occurred in ~30% of mothers and infants. SARS-CoV-2 sequences obtained from stool were related to contemporaneously circulating variants. Conclusions: These data indicate that postpartum Kenyan women and their infants were at high risk for SARS-CoV-2 infection in 2020, and that antibody responses waned rapidly. However, most cases were asymptomatic and healthy women living with HIV did not have a substantially increased risk of infection or severe COVID-19.

A multitude of enzyme‐linked immunosorbent assays (ELISAs) has been developed to detect severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) antibodies since the coronavirus disease 2019 pandemic started in late 2019. Assessing the reliability of these assays in diverse global populations is critical. This study compares the use of the commercially available Platelia Total Ab Assay (Bio‐Rad) nucleocapsid ELISA to the widely used Mount Sinai spike IgG ELISA in a Kenyan population seroprevalence study. Using longitudinal plasma specimens collected from a mother–infant cohort living in Nairobi, Kenya between May 2019 and December 2020, this study demonstrates that the two assays have a high qualitative agreement (92.7%) and strong correlation of antibody levels (R2 = 0.973) in repeated measures. Within this cohort, seroprevalence detected by either ELISA closely resembled previously published seroprevalence estimates for Kenya during the sampling period and no significant difference in the incidence of SARS‐CoV‐2 antibody detection by either assay was observed. Assay comparability was not affected by HIV exposure status. These data support the use of the Platelia SARS‐CoV‐2 Total Ab ELISA as a suitable high‐throughput method for seroprevalence studies in Kenya.