Pregnant people face increased risk of severe COVID-19. Current guidelines recommend updated COVID-19 vaccination (2023-2024) for those aged ≥ 6 months, irrespective of pregnancy status. To refine recommendations for pregnant people, further data are needed. Using a test-negative design, we evaluated COVID-19 vaccine effectiveness against medically attended COVID-19 with COVID-19-like illness among pregnant people aged 18 to 45 years during June 2022 to August 2023. When doses were received during pregnancy, vaccine effectiveness was 52% (95% CI, 29%-67%); when received <6 months prior to pregnancy, 28% (95% CI, 11%-42%); and when received ≥ 6 months prior to pregnancy, 6% (95% CI, -11% to 21%). Pregnant people should stay up-to-date with recommended COVID-19 vaccination.