Skip to content

Prior Covid Infection Protected Better From Delta Than Vaccine Alone, CDC Finds

  • CDC study shows Covid protection created by earlier infections
  • Vaccination is still the safest route to prevention, CDC says
Video player cover image
How the Global Vaccine Campaign Has Succeeded—and Failed
Updated on

Prior infection with Covid-19 gave at least as much protection from a repeat bout of the coronavirus as vaccination during the rise of the delta variant, according to a U.S. government study. 

Before delta arose last summer, vaccinated people with no previous cases were about half as likely to be diagnosed with Covid as unvaccinated people who’d had the disease earlier, according to a U.S. Centers for Disease Control and Prevention analysis of data from California and New York. After delta became dominant in late June and July, those with prior cases alone were better protected than those who’d only received vaccines, without an earlier infection.