COVID outbreak in party town shows how the pandemic could end

It was meant to be a summer vacation to celebrate. Thousands of revelers flocked to Provincetown, Massachusetts, for the July Fourth holiday, fully immunized against COVID-19 and ready to enjoy new freedoms, including socializing without face masks. 

Instead, the weather turned cool and rainy, and the festivities shifted indoors to pubs, clubs and private homes, creating a crucible for the effectiveness of vaccines used to contain the uber-transmissible delta variant. More than 1,000 COVID cases ensued over the following two weeks, rocking confidence in the inoculations and prompting the U.S. Centers for Disease Control and Prevention to reinstate an indoor masking mandate. 

Four months later, researchers studying those who contracted the virus are gaining important insights into the immunity-bolstering effects of natural infection after vaccination. Importantly, their findings offer clues about the immune protection needed for the coronavirus to cease being a public-health menace and, ultimately, to end the pandemic.