Here’s how many breakthrough COVID-19 cases have occurred in Mass. 

The Bay State has seen 6,373 breakthrough cases as of July 24, according to the Department of Public Health. 

David L Ryan/Globe Staff

Massachusetts is seeing a growing number of breakthrough COVID-19 cases in fully vaccinated individuals. 

Breakthrough Cases:

The Bay State has seen 6,373 breakthrough cases, as of July 24, according to data released by the Department of Public Health on Thursday. Of that number, 361 people were hospitalized and 91 individuals with breakthrough cases have died. 

According to the state, the breakthrough cases represent 0.15% of the 4,351,752 people who have been fully vaccinated in Massachusetts. The hospitalized breakthrough cases represent 0.009% of fully vaccinated individuals; the deaths 0.002%.

According to WCVB, the number of breakthrough cases jumped up from 5,166 cases reported as of July 17 and 4,450 reported the previous week.


The state has seen a rise in its COVID-19 infection rates in recent weeks, driven, according to Gov. Charlie Baker and public health officials, by the super-contagious Delta variant and gatherings held around the July Fourth holiday. 

Provincetown has seen a surge of hundreds of cases, many among fully vaccinated individuals. New data from that outbreak, which showed individuals who were vaccinated were transmitting the virus to other fully vaccinated people, was one of the factors for the Centers for Disease Control and Prevention updating its guidelines for indoor mask use earlier this week, the Washington Post reports

The federal agency is now recommending that all individuals — regardless of their vaccination status — wear face coverings in public, indoor spaces in counties experiencing “substantial” or “high” levels of COVID-19. That threshold is defined by the CDC as at least 50 new cases per 100,000 people in the last week or averaging a positive test rate above 8 percent.

Provincetown is among a few Massachusetts municipalities that have already moved to update mask mandates in the face of rising cases. But Gov. Charlie Baker has said his administration is still mulling the change in CDC guidelines. 


“We just got it and we’re reviewing it, and we’ll have more to say about it later,” Baker told reporters Wednesday.

Baker also said Wednesday his administration is “considering” additional changes the CDC suggested this week, recommending that everyone — teachers, staff, students, visitors — wear masks in schools this fall, even if they’re vaccinated. The governor previously said his administration had no plans to alter its stance of lifting all COVID-19 restrictions for the upcoming school year.


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