The study, published on Friday, suggested the Delta variant of the virus was highly contagious. The outbreak occurred in Provincetown on Cape Cod, according to Barnstable County health authorities.
The CDC study found vaccinated individuals had a similar amount of virus presence as the unvaccinated, suggesting that, unlike with other variants, vaccinated people infected with the Delta variant could transmit the virus, the CDC said.
CDC Director Rochelle Walensky said this was a "pivotal discovery" leading to CDC's recommendation this week that masks be worn in areas where cases were surging as a precaution against possible transmission by fully vaccinated people. (...)
