Massachusetts Governor Charlie Baker tours a pooled COVID-19 testing program on Friday during a visit to the Nock-Molin Middle School in Newburyport.

About 950 schools in Massachusetts are administering weekly pooled COVID-19 tests to about 300,000 teachers, students and staff, including at least three Berkshire County districts.

North Adams Public Schools, Berkshire Hills Regional School District and Mount Greylock Regional School District have all been accepted into the program.

Gov. Charlie Baker detailed the statewide numbers on Friday from the Nock-Molin School in Newburyport, which is among the participants in the state's pool testing program, an initiative Baker announced last month with the goal of providing a more efficient COVID-19 screening method for schools repopulating their classrooms after months of remote learning.

"To get to the point where this thing is really starting to rock and roll is a real pleasure, I think, for all of us who were looking to find a relatively uncomplicated way for schools to implement a weekly surveillance program, and you folks were one of the first in line," Baker said.

In North Adams, Superintendent Barbara Malkas said the program would provide "better surveillance" and "real time data to be responsive to community spread within the schools." 

Baker and Education Commissioner Jeff Riley said they expect to see more school districts get in on the pool testing program, which involves laboratories testing multiple swabs in a single batch.

Out of the state's 400 school districts, Riley said about 159 are now involved in pooled testing, and he expects to see "significantly more" participating in about a week and a half.

"If people want to play in the pooled testing pool, we'd love to have everybody in," Baker said.

The state is covering initial costs, and the Department of Elementary and Secondary Education has said that after March 28, districts and schools that wish to continue with the program will be able to do so "by purchasing services from a statewide contract."

Riley said that after the state-funded period, districts could use their federal stimulus money to pay for the pooled tests.

The school visit came a day after lawmakers grilled Baker on the state's vaccine rollout and on the heels of an announcement earlier this week from Baker and Riley that the administration wants elementary school students learning in-person full time by April.

Teachers unions and some lawmakers have responded to Tuesday's announcement by calling for swift vaccination of school personnel.

Baker on Friday reiterated his hopes that amped-up production by vaccine-makers Moderna and Pfizer and pending authorization of the single-shot Johnson & Johnson vaccine could dramatically increase the supply of doses that are available to states. Such a boost, he said, would help Massachusetts more quickly move through the current eligible populations and onto the next group, which includes teachers and other essential workers.

"Our problem at this point isn't availability of the capacity to deliver vaccinations," he said. "Our problem is we have more capacity than we have vaccines that are available."

Scituate Superintendent William Burkhead posted online Friday a letter that he wrote to Baker, which said vaccinated school personnel "will certainly perform their jobs better with the peace of mind that they are unlikely to become seriously ill" and asked the governor to advocate for a regional approach to educator vaccination using the Johnson & Johnson shot once it is ready.

"We are hopeful that a concerted effort to have the J&J vaccine distributed to cities and towns for vaccination with the goal of vaccinating teachers and staff will allow them to focus on educating and supporting children and begin address the significant social emotional challenges the pandemic has created for students and families," Burkhead wrote. "This would in no way interrupt the flow of the Pfizer and Moderna vaccines to the Mass and regional vaccination sites."