SARS-CoV-2 surveillance and vaccine effectiveness among dental healthcare workers during the omicron surge.

Dental students and practitioners may have an increased risk of COVID-19 infection due to frequent aerosol-generating procedures (AGP) and close patient contact. We examined the role of vaccination status, work role, and AGP frequency on positive SARS-CoV-2 PCR surveillance test using a Cox proportional hazards regression and weighted for dropout. A total of 410 dental health workers (200 students, 104 faculty, and 106 staff) had 8,270 screening tests performed between May 2020 and February 2022, with 158 positive tests; 60 (38%) occurred in January 2022. Omicron had a significant impact on vaccination effectiveness. Vaccine effectiveness within < 4 months was 91% (HR: 0.09,95% CI: 0.02-0.40) prior to Omicron, which decreased after its emergence. Work role was not associated with risk of positive test. Reported AGP frequency was also not associated with positive test risk; however, these analyses were limited to a subset of participants and should be considered exploratory. More than a third of all positive tests occurred during one month of Omicron. We found a high vaccine effectiveness prior to the Omicron surge, which decreased after the emergence of Omicron. Our results support encouraging dental healthcare workers (DCWs) to maintain up-to-date vaccination and continue engaging in preventive measures.