COVID-19 infection was very low in a cohort of vaccinated California healthcare workers (HCWs) amid a surge of new cases, according to a research letter yesterday in the New England Journal of Medicine.University of California researchers evaluated COVID-19 infection rates in 36,659 HCWs on the San Diego and Los Angeles campuses vaccinated with at least one dose of the Moderna or Pfizer/BioNTech vaccine from Dec 16, 2020, to Feb 9, 2021.
In that timeframe, 28,184 (77%) received the second dose of vaccine.Of the 36,659 vaccinated HCWs, 379 (1.0%) tested positive for COVID-19 1 or more days after vaccination, 71% of them within the first 2 weeks after the first dose.