SEEKING TO REASSURE schools reopening this fall with in-person learning, Gov. Charlie Baker said he is launching a statewide mobile testing program that can be deployed if a handful of staff or students come down with COVID-19.

“This program will be designed to quickly deliver testing resources for students and school personnel if there are multiple cases in a cohort that require larger-scale testing than a community may have access to currently,” Baker said.

Marylou Sudders, the secretary of health and human services, said the mobile testing program would be deployed to K-12 schools at the request of the local board of health if there are two to three non-related individuals who contract COVID-19 in a class, a grade, on the staff, or on a bus over a 14-day period.

“We see this as a response to school concerns about cluster development,” Sudders said.

She and the governor said additional guidance on the program would be made available over the coming weeks.

Baker and Sudders touted Massachusetts as one of the top states for testing with results coming back in about two days on average. Sudders said the state ranks sixth in the nation in terms of tests per capita.

Baker, who is facing pushback from teacher unions on his push for students to return to classrooms, said the Department of Elementary and Secondary Education has helped schools get ready to reopen by providing “comprehensive, science-based plans” on student sports, transportation, and classroom configuration.

On Monday, Baker told reporters that 70 percent of Massachusetts districts have indicated they are planning a hybrid or in-person return this fall.

Baker noted that the “best science” has been used to develop reopening plans, and that science panels had approved the measures. One of the barometers he mentioned is the case rate in municipalities, adding that “more than 73 percent of communities either saw a downturn in numbers or stayed the same” over the last two weeks.

Baker was asked about a Wednesday State House rally by teachers’ unions opposed to his push for in-person teaching and responded that he is “asking people to respect the science.” The teacher groups have been pushing districts to allow them to start school remotely out of concern for infection spread.

Lt. Gov. Karyn Polito repeated that flu shots will now be required for all students in Massachusetts schools, from those six months old through college with a handful of exceptions, a development announced by the Department of Public Health on Wednesday. Students learning from home will not be exempt.

Students older than 6 months must be vaccinated by December 31, unless either a medical or religious exemption is provided.