With holidays looming, scientists point to additional data showing value of vaccines

Vaccinated people who get COVID-19 are "much less infectious more rapidly."

The summer surge of COVID-19, fueled by the delta variant, raised alarm bells among scientists and citizens alike that unlike prior variants of the virus, this one was different.

Those fears solidified in July, when the Centers for Disease Control and Prevention reported an outbreak in Provincetown, Massachusetts, among mostly vaccinated people. This early data hinted, alarmingly, that the delta variant could be equally likely to spread among the vaccinated and the unvaccinated.

Prior to the emergence of the delta variant, the risk of spreading the virus while vaccinated appeared to be so low the CDC said it was safe for vaccinated people to ditch their masks. But CDC Director Rochelle Walensky described the Provincetown findings as "concerning," and she promptly reversed the agency's mask guidelines for vaccinated people, prompting renewed fear and uncertainty about the efficacy of vaccines against variants.

"I think the people who are really concerned are parents with children under 12 who are concerned that even if they're vaccinated, they could have a breakthrough infection and transmit it to their unvaccinated children," said Dr. Anna Durbin, an associate professor at the Johns Hopkins University School of Medicine. "I get that."