COVID-19 vaccine uptake and associated risk factors among first antenatal care attendees in Zambia, 2021-2022: a repeated cross-sectional study

Introduction   Pregnant women are considered a high-risk group for COVID-19, and a priority for vaccination. Routine antenatal (ANC) care provides an opportunity to track trends and factors associated with vaccine uptake. We sought to evaluate COVID-19 vaccine uptake among pregnant women attending ANC in Zambia.   Methods  We conducted a repeated cross-sectional study in 39 public health facilities in four districts in Zambia from September 2021 to September 2022. Pregnant women who were aged 15-49 years were enrolled during their first ANC visit. Every month, ~20 women per facility were interviewed during individual HIV testing and counseling. We estimated vaccine uptake as the proportion of eligible participants who self-reported having received the COVID-19 vaccine.   Results   A total of 9,203 pregnant women were screened, of which 9,111 (99%) were eligible and had vaccination status. Of the 9,111 included in the analysis, 1,818 (20%) had received the COVID-19 vaccine during the study period, with a trend of increasing coverage with time (0.5% in September 2020, 27% in September 2022). Conversely, 3,789 (42%) reported not being offered a COVID-19 vaccine. We found that older age, education, employment status, and prior COVID-19 infection were significantly associated with vaccine uptake.     Conclusion  COVID-19 vaccine uptake among pregnant women was lower than estimates from the general population (27% across the four districts in September 2022), pointing to missed opportunities to protect this high-risk group. ANC visits were a viable point for conducting COVID-19 surveillance. Incorporating the vaccine as part of the routine ANC package might increase coverage in this group. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The “Assessing SARS-CoV-2 Seroprevalence during Routine Antenatal Care Visits in Zambia” was supported by the US Centers for Disease Control (CDC) under the terms of award number NU2GGH002251. The terms of this arrangement have been reviewed and approved by the Centres for Disease Control and Prevention in accordance with its policy on objectivity in research. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This study was reviewed and approved by the National Health Research Authority (NHRA), a statutory body under the Zambian MoH, and following the US Centers for Disease Control and Prevention (CDC) human research protection procedures as the CDC investigators were not engaged (i.e., did not interact with human subjects or have access to identifiable data or specimens for research purposes). It was also reviewed and approved, particularly for the Chadiza sites, by the University of Zambia Biomedical Research Ethics Committee (UNZABREC) and PATH's Research Ethics Committee (PATH REC). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The authors confirm that the data supporting the findings of this study are available within the article. Raw data that support the findings of this study are available from the corresponding author upon request.