COVID-19 booster vaccination during pregnancy enhances maternal binding and neutralizing antibody responses and transplacental antibody transfer to the newborn.

The immune response to COVID-19 booster vaccinations during pregnancy for mothers and their newborns and the functional response of vaccine-induced antibodies against Omicron variants are not well characterized. We conducted a prospective, multicenter cohort study of participants vaccinated during pregnancy with primary or booster mRNA COVID-19 vaccines from July 2021 to January 2022 at 9 academic sites. We determined SARS-CoV-2 binding and live virus and pseudovirus neutralizing antibody (nAb) titers pre- and post-vaccination, and at delivery for both maternal and infant participants. Immune responses to ancestral and Omicron BA.1 SARS-CoV-2 strains were compared between primary and booster vaccine recipients in maternal sera at delivery and in cord blood, after adjusting for days since last vaccination. A total of 240 participants received either Pfizer or Moderna mRNA vaccine during pregnancy (primary 2-dose series: 167; booster dose: 73). Booster vaccination resulted in significantly higher binding and nAb titers, including to the Omicron BA.1 variant, in maternal serum at delivery and in cord blood compared to a primary 2-dose series (range 0.44-0.88 log10 higher, p < 0.0001 for all comparisons). Live virus nAb to Omicron BA.1 were present at delivery in 9 % (GMT ID50 12.7) of Pfizer and 22 % (GMT ID50 14.7) of Moderna primary series recipients, and in 73 % (GMT ID50 60.2) of mRNA boosted participants (p < 0.0001), although titers were significantly lower than to the D614G strain. Transplacental antibody transfer was efficient for all regimens with median transfer ratio range: 1.55-1.77 for IgG, 1.00-1.78 for live virus nAb and 1.79-2.36 for pseudovirus nAb. COVID-19 mRNA vaccination during pregnancy elicited robust immune responses in mothers and efficient transplacental antibody transfer to the newborn. A booster dose during pregnancy significantly increased maternal and cord blood binding and neutralizing antibody levels, including against Omicron BA.1. Findings support the use of a booster dose of COVID-19 vaccine during pregnancy.

Impact of the COVID-19 pandemic on obstetrical care at a tertiary care facility in Mombasa, Kenya: Time-series analyses and staff perspectives.

The COVID-19 pandemic caused disruption in healthcare delivery due to reductions in both health facility capacity and care-seeking behavior. For women experiencing obstetric complications, access to comprehensive emergency obstetric care is critical for maternal and child health. In Kenya, pandemic-related restrictions began in March 2020 and were compounded by a healthcare worker strike in December 2020. We examined medical record data at Coast General Teaching and Referral Hospital, a large public hospital, and conducted staff interviews to understand how healthcare disruptions impacted care delivery and perinatal outcomes. Routinely collected data from all mother-baby dyads admitted to the Labor and Delivery Ward from January 2019 through March 2021 were included in interrupted time-series analyses. Outcomes included number of admissions and proportion of deliveries that resulted in caesarean sections and adverse birth outcomes. Interviews were conducted with nurses and medical officers to understand how the pandemic impacted clinical care. Pre-pandemic, the ward averaged 810 admissions/month, compared to 492 admissions/month post-pandemic (average monthly decrease: 24.9 admissions; 95% CI: -48.0, -1.8). The proportion of stillbirths increased 0.3% per month during the pandemic compared to the pre-pandemic period (95% CI: 0.1, 0.4). No significant differences were seen in the proportion of other adverse obstetrical outcomes. Interview results suggested that pandemic-related disruptions included reduced access to surgical theaters and protective equipment, and absence of COVID-19 guidelines. While these disruptions were perceived as impacting care for high-risk pregnancies, providers believed that overall quality of care did not diminish during the pandemic. However, they expressed concern about a likely increase in at-home births. In conclusion, while the pandemic had minimal adverse impact on hospital-based obstetrical outcomes, it reduced the number of patients able to access care. Emergency preparedness guidelines and public health messaging promoting timely obstetrical care are needed to ensure continuation of services during future healthcare disruptions.

Comparison of nucleocapsid and spike antibody ELISAs for determining SARS-CoV-2 seropositivity in Kenyan women and infants.

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.

HIV and SARS-CoV-2 infection in postpartum Kenyan women and their infants.

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.

Assessing the sustainability of the Systems Analysis and Improvement Approach to increase HIV testing in family planning clinics in Mombasa, Kenya: results of a cluster randomized trial.

BACKGROUND: In Kenya, HIV incidence is highest among reproductive-age women. A key HIV mitigation strategy is the integration of HIV testing and counseling (HTC) into family planning services, but successful integration remains problematic. We conducted a cluster-randomized trial using the Systems Analysis and Improvement Approach (SAIA) to identify and address bottlenecks in HTC integration in family planning clinics in Mombasa County, Kenya. This trial (1) assessed the efficacy of this approach and (2) examined if SAIA could be sustainably incorporated into the Department of Health Services (DOHS) programmatic activities. In Stage 1, SAIA was effective at increasing HTC uptake. Here, we present Stage 2, which assessed if SAIA delivery would be sustained when implemented by the Mombasa County DOHS and if high HTC performance would continue to be observed. METHODS: Twenty-four family planning clinics in Mombasa County were randomized to either the SAIA implementation strategy or standard care. In Stage 1, the study staff conducted all study activities. In Stage 2, we transitioned SAIA implementation to DOHS staff and compared HTC in the intervention versus control clinics 1-year post-transition. Study staff provided training and minimal support to DOHS implementers and collected quarterly HTC outcome data. Interviews were conducted with family planning clinic staff to assess barriers and facilitators to sustaining HTC delivery. RESULTS: Only 39% (56/144) of planned SAIA visits were completed, largely due to the COVID-19 pandemic and a prolonged healthcare worker strike. In the final study quarter, 81.6% (160/196) of new clients at intervention facilities received HIV counseling, compared to 22.4% (55/245) in control facilities (prevalence rate ratio [PRR]=3.64, 95% confidence interval [CI]=2.68-4.94). HIV testing was conducted with 60.5% (118/195) of new family planning clients in intervention clinics, compared to 18.8% (45/240) in control clinics (PRR=3.23, 95% CI=2.29-4.55). Interviews with family planning clinic staff suggested institutionalization contributed to sustained HTC delivery, facilitated by low implementation strategy complexity and continued oversight. CONCLUSIONS: Intervention clinics demonstrated sustained improvement in HTC after SAIA was transitioned to DOHS leadership despite wide-scale healthcare disruptions and incomplete delivery of the implementation strategy. These findings suggest that system interventions may be sustained when integrated into DOHS programmatic activities. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02994355) registered on 16 December 2016.

Multi-site observational maternal and infant COVID-19 vaccine study (MOMI-vax): a study protocol.

BACKGROUND: Pregnant women were excluded from investigational trials of COVID-19 vaccines. Limited data are available to inform pregnant and postpartum women on their decisions to receive a COVID-19 vaccine. METHODS: The goal of this observational, prospective cohort study is to evaluate the immunogenicity and safety of various Emergency Use Authorization (EUA) or licensed COVID-19 vaccines administered to pregnant or lactating women and describe the transplacental antibody transfer and kinetics of antibodies in mothers and infants. The study is adaptive, allowing additional groups to be added as new vaccines or vaccine regimens are authorized. Up to 20 clinical research institutions in the United States (U.S.) will be included. Approximately 200 pregnant women and 65 postpartum women will be enrolled per EUA or licensed COVID-19 vaccine formulation in the U.S. This study will include pregnant and postpartum women of all ages with and without chronic medical conditions. Their infants will be enrolled and followed beginning at birth in the pregnant cohort and beginning at the earliest possible time point in the postpartum cohort. Blood samples will be collected for immunogenicity outcomes and pregnancy and birth outcomes assessed among women and infants. Primary analyses will be descriptive and done by vaccine type and/or platform. DISCUSSION: Given the long-standing and legitimate challenges of enrolling pregnant individuals into clinical trials early in the vaccine development pipeline, this study protocol describes our current study and provides a template to inform the collection of data for pregnant individuals receiving COVID-19 or other vaccines. TRIAL REGISTRATION: NCT05031468 .