BOSTON — The number of communities at high risk for COVID-19 more than doubled in the past two weeks amid mounting concerns about another surge of infections.
Fifty-five cities and towns are now coded "red" for COVID-19 transmission, according to the state Department of Public Health. That's up from 32 communities last week and 20 two weeks ago. The designation is based on the number of cases and the positivity rate in COVID-19 testing, scaled based on population.
Health officials say the uptick, which comes as more people are vaccinated, is troubling and highlights the need for people to continue wearing masks, practice social distancing and take other precautions with highly contagious strains of the coronavirus circulating locally.
"It's a particular concern with the increased reopening process, and restaurants and other retail businesses returning to full capacity," said Dr. David Hamer, an infectious disease expert and professor at Boston University's School of Public Health and School of Medicine. "At the same time, we have clear evidence that there are more contagious strains of the virus in the community."
Hamer said the state should consider easing or even rolling back some of its reopening plans until a larger portion of the population is vaccinated.
Several North of Boston cities and towns were listed as high-risk "red" communities — including Lawrence, Lynn and Peabody — as their rates increased over the past week. Other communities such as Salem, Andover, Gloucester, Wenham and Salisbury also reported higher rates of infection over previous weeks.
The concerns about another wave of COVID-19 infections come as more Massachusetts residents are vaccinated against the virus. More than 3.9 million doses have been administered as of Monday, with more than 1.4 million people fully vaccinated. The state has about 6.9 million residents.
Dr. David Rosman, president of the Massachusetts Medical Society, said the state is making progress. Still, only 1 in 5 residents have been vaccinated so far.
"When 80% of the population still hasn't been vaccinated, the vast majority remain vulnerable to COVID," he said.
Rosman said the data shows COVID-19 cases shifting in demographics from older people who have been vaccinated to younger people who have not yet gotten their shots.
"This is an age group more likely to get together and socialize, and I think we're seeing the consequences of that," he said.
The majority of positive COVID-19 tests reported in the past two weeks were among people 19 years old and younger, according to state data.
Many school districts have ramped up pool testing of students as they prepare for a resumption of full-time class instruction later this month.
Public schools reported more than 1,000 COVID-19 cases involving students and staff last week — the highest number since the state began tracking the data last year. That included 801 students and 244 educators and school staff who reported new positive COVID-19 tests, which is up from 669 two weeks ago.
State education officials point out the cases represent only a fraction of more than 660,000 students and staff in hybrid or in-class instruction.
Gov. Charlie Baker has acknowledged the uptick in cases and hospitalizations, and has stressed the need to keep taking precautions until more vaccines are available.
Christian M. Wade covers the Massachusetts Statehouse for North of Boston Media Group’s newspapers and websites.