COVID-19 mutations drive up virus cases in Mass.

Apr. 12—BOSTON — The number of communities with elevated COVID-19 infection levels jumped again last week, as health officials say mutations of the virus continue to spread in Massachusetts.

At least 77 cities and towns are now listed as high-risk for COVID-19 transmission, according to the state Department of Public Health. That's up from 55 the previous week and 20 three weeks ago

The designation is based on the number of active cases and the positivity rate on COVID-19 tests, scaled based on population.

Several North of Boston communities that were already listed as high-risk "red" communities — including Lawrence, Methuen, and Peabody — saw rates remain flat or increase.

Meanwhile, the state is also reporting more cases of COVID-19 mutations.

As of Monday, the health department reported that laboratory tests had detected at least 1,405 cases of three different COVID-19 variants to the U.S. Centers for Disease Control and Prevention. That's up from 1,068 less than two weeks ago.

A majority of the cases were B.1.1.7, a variant first detected in the United Kingdom which has become the dominant strain in the U.S. Cases tied to other variants, B.1.351 and P.1, which were first detected in South Africa and Brazil, are also on the rise, according to health officials.

Nationwide, at least 19,554 cases of the B.1.1.7 variant have been reported, according to the CDC. There are 324 cases of B.1.351 in 36 states and 434 P.1 cases in 28 states.

As of Thursday, Massachusetts had the highest number of cases of the Brazilian strain nationwide, or 113, the federal agency reported.

Essex County has reported the third-highest number of COVID-19 variant cases, or 219, according to state data.

Meanwhile, the state's public schools reported nearly 1,000 COVID-19 cases involving students and staff last week — a slight decline over the previous week — as most schools prepare for a return to full-time, in-person instruction.

That figure included 821 students and 157 staff who reported positive COVID-19 tests.

State education officials point out the cases represent only a fraction of more than 660,000 students and staff currently in hybrid or in-class instruction.

Health officials in Massachusetts reported 1,376 new cases of COVID-19 and 19 new deaths on Monday.

The rising infection rate comes as more people get vaccinated against the virus.

More than 4.5 million doses have been administered as of Monday, with more than 1.7 million people fully vaccinated. The state has about 6.9 million residents.

Gov. Charlie Baker acknowledged the uptick in cases and hospitalizations and stressed the need for people to continue wearing masks, practice social distancing and get vaccinated.

"We would encourage everybody who will be eligible to sign up and schedule a vaccine when they are eligible," he said at a briefing on Monday. "The vaccine saves lives."

Christian M. Wade covers the Massachusetts Statehouse for North of Boston Media Group's newspapers and websites. Email him at cwade@cnhinews.com