COVID-19 vaccination rates are decreasing despite vaccination being the most effective tool against severe disease from COVID-19. From October 1, 2022, to February 1, 2023, we conducted a cross-sectional study among adults in the Vaccine Safety Datalink about attitudes and beliefs regarding bivalent COVID-19 Omicron booster vaccine (hereafter referred to as COVID-19 bivalent vaccine) stratifying by vaccination status and race and ethnicity. Analysis was weighted for response and selection bias. The response rate was 27% (385/1430); 33% [95% CI: 21%-44%] of respondents were 'fully vaccinated' (had received COVID-19 bivalent vaccine), 54% [42%-67%] were partially vaccinated, and 13% [7%-19%] were unvaccinated. Fully vaccinated adults were more likely to consider COVID-19 bivalent vaccine 'very effective' (64%, [43%-86%]) at preventing hospitalization due to COVID-19 than partially (31%, [12%-50%]) or unvaccinated (2%, [0%-6%]) adults. Fully vaccinated adults were more likely to report COVID-19 bivalent vaccine was 'very safe' (83%, [69%-98%]) than partially (43%, [23%-63%]) or unvaccinated adults (2%, 0%-6%). Non-Hispanic White adults were more likely to report COVID-19 bivalent vaccine was 'very safe' (71%, [54%-87%]) than Non-Hispanic Black (36%, [21%-50%]) and Hispanic (26%, [7%-45%]) adults. A dose-response effect between vaccination status and perceptions of COVID-19 bivalent vaccine safety and effectiveness was observed, with fully vaccinated respondents having the most favorable attitudes. Racial and ethnic differences in perceived vaccine safety were also found. Improved communication about vaccine effectiveness and safety is key to improving low vaccination rates.