274 vaccinated people came down with symptoms of COVID-19 after an outbreak in Massachusetts, the CDC said.
The Centers for Disease Control and Prevention is urging local health authorities to consider heightened prevention strategies like « universal masking » for public indoor settings, particularly when it comes to large indoor gatherings with travelers. It cited new data from a delta variant outbreak in Massachusetts that led to hundreds of coronavirus infections — many among fully vaccinated travelers. The CDC, in the agency’s Morbidity and Mortality Weekly Report, also published more details about the « pivotal discovery » that prompted federal health officials to earlier this week. Tests used to diagnose cases linked to the Massachusetts outbreak had similar « cycle threshold » values among both unvaccinated and fully vaccinated « breakthrough » cases, suggesting both groups could be carrying similar loads of the virus. « High viral loads suggest an increased risk of transmission and raised concern that, unlike with other variants, vaccinated people infected with Delta can transmit the virus, » CDC Director Rochelle Walensky said in a statement.
