CDC details Massachusetts outbreak that sparked mask update
The CDC released data Friday on the Cape Cod coronavirus outbreak that pushed the agency to update its mask guidance, showing that nearly three-quarters of confirmed cases were among the fully vaccinated.
The Massachusetts Department of Public Health’s analysis of COVID-19 samples from the outbreak determined that fully vaccinated patients carried similar amounts of the virus as unvaccinated patients.
The results from the mostly delta variant samples indicate that fully vaccinated people can potentially transmit and spread the strain, according to the CDC’s Morbidity and Mortality Weekly Report.
The report noted that microbiological studies are needed to confirm that similarity in the viral load to determine whether fully vaccinated people can transmit the virus.
By the numbers: The state health department identified 469 COVID-19 cases among Massachusetts residents who went to Provincetown, a popular vacation destination in Barnstable County, in the month of July, including 346 fully vaccinated people.
A total of 79 percent of the breakthrough cases were symptomatic. Five patients were hospitalized, four of whom were fully vaccinated, and no deaths were reported. Two of the fully vaccinated hospitalized patients had “underlying medical conditions.”
Why it matters: CDC Director Rochelle Walensky cited this data Tuesday when announcing the new mask recommendations for even fully vaccinated people to cover their faces in indoor public settings in counties with “substantial” and “high” COVID-19 transmission.
“This finding is concerning and was a pivotal discovery leading to CDC’s updated mask recommendation,” she said in a Friday statement.
