Supporting Information_Raw Data_190624

<b>Introduction</b>Pregnant women are considered a high-risk group for COVID-19, and a priority for vaccination. Routine antenatal care (ANC) 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 and assess the factors associated with vaccine uptake in Zambia.<b>Methods</b>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 aged 15-49 years were enrolled during their first ANC visit. Every month, ~20 women per facility were interviewed during individual HIV counseling and testing. We estimated vaccine uptake as the proportion of eligible participants who reported receiving the COVID-19 vaccine.<b>Results </b>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 women aged 40-49 years, had no education or attained some primary school education, were not employed, and had prior COVID-19 infection were significantly associated with vaccine uptake.<b>Conclusion</b>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.