Incidence of SARS-CoV-2 infection in health care workers after a single dose of mRNA-1273 vaccine.

Gupta K, O'Brien WJ, Bellino P, et al. Incidence of SARS-CoV-2 infection in health care workers after a single dose of mRNA-1273 vaccine. JAMA Network Open. 2021; 4(6): e2116416. doi: 10.1001 / jamanetworkopen.2021.16416

Commentary

This study was conducted in a cohort study, resulting in a total of 4028 health care workers, of whom 3367 (83.6%) were vaccinated during the period SARS-CoV-2 infection was confirmed in 107 health care workers (39 vaccinated and 68 unvaccinated) by RT-PCR confirmed by RT-PCR, most infections (75 infections [73.5%]) were symptomatic, and 7 (6.5%) were identified during routine surveillance.

Vaccinated and unvaccinated RT-PCR positive health care workers do not differ significantly by age, gender, race, percentage of nursing staff, or clinical presentation. Of the 39 SARS-COV-2 positive vaccinated healthcare workers, 26 (66.7%) received one dose of vaccine by December 29, 2020. The clinical efficacy of the vaccine was 50.3% for the entire 42 days. The follow-up period, days 8 to 42, was 77.5%, and days 15 to 42, 95.0%. When the analysis was limited to the first 28 days of the study, thereby excluding the effect of dose 2, the clinical efficacy was similar.

However, there are limitations to this study, including the observational design, the small number of participants from a single center, and the inability to adjust for confounding characteristics. Therefore, the results may not generalize to other settings with different demographic characteristics.