Is it time to get serious about masking inside again in Massachusetts?

People wearing masks this summer inside Boston's Quincy Market. Boston requires everyone, vaccinated or not, to wear a mask in indoor public spaces.Suzanne Kreiter/Globe Staff

With COVID-19 cases on the rise as the holidays begin, some experts are recommending that everyone, vaccinated or not, should wear masks in indoor public spaces in Massachusetts.

“I recommend mask wearing for all in indoor spaces and hope that stores would institute masking policies while case numbers are going up, especially as holiday shopping can be a very busy time,” said Dr. Paul Sax, clinical director of the Division of Infectious Diseases at Brigham and Women’s Hospital.

Dr. Cassandra Pierre, the associate hospital epidemiologist and director of public health programs at Boston Medical Center, said she also recommended mask-wearing for all in indoor public spaces. “The masks are still important because we have a small but significant percentage of the population that is unvaccinated,” she said.

A mask not only protects the wearer from being infected, it also protects the wearer from infecting others, she pointed out. “They work for everyone,” she said. “We are all connected. For our own health and for the health of others, it makes a lot of sense.”

The two doctors’ recommendations aligned with the US Centers for Disease Control and Prevention, which is currently recommending masking for everyone in indoor public spaces in all of Massachusetts except Nantucket.

The CDC recommends that everyone, even fully vaccinated people, wear masks in public indoor spaces where community transmission of the virus is “substantial or high.” Currently, roughly 87 percent of US counties meet that threshold, which is defined as at least 50 new cases weekly per 100,000 residents.

All the Massachusetts mainland counties have “high” transmission, while Dukes County, which covers the island of Martha’s Vineyard, has “substantial transmission.” Nantucket has “moderate” transmission so the mask recommendation doesn’t apply to it, according to data posted on the CDC website Wednesday.

Julia Raifman, an assistant professor of health law, policy, and management at the Boston University School of Public Health, also said she believed all people should wear masks in indoor public spaces at what she believes is a crucial point in the pandemic.

She said the state should issue a mask mandate for indoor public spaces, warning, “I think we’re on track for Massachusetts to be really hard hit just in time for the winter holidays.”

“Mask policies allow us to be more safely around each other when there is a surge,” she said. “Mask policies will help us reduce the need for further measures that nobody wants.”

Dr. Howard Koh, a former US assistant secretary of health and human services and Massachusetts public health commissioner, said: “In this long and protracted COVID battle, prematurely loosening mask requirements has allowed the enemy virus to continue to wreak havoc. Until the pandemic is declared behind us, all options about strengthening indoor mask guidance should be back on the table.”

“On the personal level, each one of us can routinely wear a mask to help all of us stay as protected as possible,” Koh, now a professor at the Harvard T.H. Chan School of Public Health, said in a statement.

The state does not have a mask mandate in effect. But it has issued a set of mask recommendations that aren’t as strong as the CDC’s.

The state recommends that people wear masks indoors if they are unvaccinated. It also recommends that people who are vaccinated wear masks if they are immunocompromised or at higher risk due to age or underlying conditions, or if they live with someone who is immunocompromised, higher risk, or an unvaccinated adult.

“The [Governor Charlie Baker] Administration has no plans to adjust the guidance at this time,” a spokeswoman for the state Executive Office of Health and Human Services said in an e-mail.

Dr. Shira Doron, an infectious disease physician who is the hospital epidemiologist at Tufts Medical Center, took a different tack from the other experts.

She said, “I support anyone who thinks they want to wear a mask anytime because I think they work.” But she also said she wouldn’t go so far as to recommend that everyone wear a mask in indoor public spaces.

She said she agreed with the state guidance, rather than the CDC’s, and no “blanket indoor mask mandate” was needed. One reason, she said, is that fears raised this summer about vaccinated people being able to spread the virus as much as the unvaccinated may have been “overblown.”

For a vaccinated, healthy person, “I think it’s time to move to personal choice” on masking, she said.

Although there is no statewide mask mandate, mandates are in effect in some Massachusetts cities and towns, including the state’s two largest cities, Boston and Worcester.

Boston officials reminded people of the city’s rules in a tweet earlier this week.

Don't forget, masks are required in all of Boston’s indoor public spaces regardless of vaccination status. Mask up, Boston!

— City of Boston (@CityOfBoston) November 22, 2021

While saying wearing masks would help blunt the pandemic, the experts emphasized that vaccinations remain crucial.

“The most important thing that people can do right now to protect themselves is to get vaccinated – either the first two shots (most important) or, for those adults who are more than 6 months since their last dose, a third shot,” Sax noted in an e-mail.

Doron said, “Vaccination is way more effective than masks and well-proven.”

Pierre called vaccinations the “pinnacle” of infection prevention efforts and “our way out of this pandemic.” But even with vaccinations, she noted, there’s still a chance of getting a breakthrough infection — and that could be reduced by wearing a mask.

“Why would you want to risk that?” she said. “This is a situation where you want to use every tool at your disposal.”

Material from Globe wire services was used in this report.