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. Of the 28,184 HCWs who received their second dose, 37 (0.1%) tested positive, 22 of them 1 to 7 days later. Eight tested positive 8 to 14 days later, and 7 did so at least 15 days later.