The nation’s top public health agency has declared that if you are fully vaccinated, “you can resume activities that you did prior to the pandemic.”

That means no more masks or physical distancing, even indoors with unvaccinated people — who are on their honor to keep masking up. No more diagnostic testing for COVID-19 if you’re vaccinated, even if you’ve been around an infected person — unless you develop symptoms.

The Centers for Disease Control and Prevention updated its guidance because the vaccines really are transformative. In the rare event that a vaccinated person still contracts a coronavirus infection, symptoms are usually mild or nonexistent, and the amount of virus is so low that it is hard to spread to others.

States and cities can make their own rules. Pennsylvania will lift its mask mandate for all residents — vaccinated or not — on June 28, or when 70% of the adult population is fully vaccinated, acting Health Secretary Alison Beam announced Thursday. Neither New Jersey nor Philadelphia has yet gone that far.

Many pandemic-weary folks welcome the freedom that the CDC says comes with vaccination. But many others remain leery because scientific understanding of the virus and its scary variants is continually evolving, and only about 40% of the country is fully vaccinated. What’s more, the vaccine doesn’t confer full protection for some people, whether because of age or certain medical conditions.

We asked some experts to share their personal perspectives on the rules lifting while the pandemic continues.

William Schaffner, infectious diseases specialist at Vanderbilt

William Schaffner, a Vanderbilt University Medical Center infectious diseases specialist, is still being cautious. Although many people in Nashville, where he lives, are vaccinated, rates are low in rural parts of Tennessee and those residents visit the city. The Pfizer and Moderna vaccines are very effective, but they are not perfect. “At its best, the vaccine is 95% effective,” he said. “I didn’t say 100%.”

Schaffner, a physician who still works full time but no longer sees patients, did not want his age published. He is, however, well past 65, which puts him at high risk for severe COVID-19 if he becomes infected. “I’m an infectious diseases doctor. I’ve seen sick patients,” he said. “I don’t want to be one of them.”

So, he’s taking a conservative approach. “I still wear the mask when I go into public spaces and I do so because I’m taking a belt and suspenders approach,” he said. By that, he means the vaccine and the mask provide better protection together than alone. He and his wife would eat inside a restaurant with another vaccinated couple, but only if the tables were spaced far apart and the wait staff is masked. He would go to a theater only if patrons were well-spaced and would likely still wear a mask. He still hasn’t gone into a gym. “There’s no way you could get me to a concert right now,” he said.

He’d like to see 80% of the population vaccinated. “I think I would start to feel much more comfortable,” he said.

He does not worry that he would spread the virus to other people. He is worried that people who are unvaccinated will go maskless and mix with everyone else. “Obviously, one of the reasons I wear any mask under the current guidelines is because I don’t trust them completely,” he said.

People who are immunocompromised, he said, should definitely keep wearing masks.

Troy Randle, Virtua Health cardiologist who had COVID-19

Troy Randle has felt comfortable for months going to indoor restaurants with limited capacity, reasoning that he has a double layer of protection against COVID-19.

A cardiologist in the Virtua Health system in New Jersey, he contracted the disease early in the pandemic, in March 2020, then followed up in December and January with two doses of the Pfizer vaccine. Preliminary studies suggest that immunity from vaccines may be more durable than natural immunity from having COVID-19.

“I looked at the vaccination kind of like a booster shot,” he said.

But he remains wary of crowded public events, in part because he experiences lingering effects from the disease.

After his initial symptoms subsided, Randle developed a blood clot that blocked an artery in his brain: a stroke. More than a year later, he sometimes feels fatigued and therefore steers clear of places where he would have to wear a mask for hours on end.

He sees patients in the office but not in the hospital. He has not been to an indoor sporting event or to a movie theater, though friends and family have discussed the possibility of renting a theater for a private showing.

Randle also is not sure yet about going to a crowded indoor bar or restaurant, once capacity limits return to normal. Yes, the number of cases has dropped dramatically, but it dropped at this time last year, too, before creeping up again, he said. So he thinks masks, hand-washing, and other precautions remain a safe bet for now.

Randle feels confident that even if he were to get the disease again, his primed immune system would ensure that the symptoms were mild. But he’d hate to see anyone else go through what he did in April 2020.

“I do think we need to open up,” he said. “I do think we need to reengage, but also be mindful that this is still present.”

Charles Haas, environmental engineer at Drexel

Last July, Charles Haas joined 239 other scientists around the world in urging the World Health Organization to acknowledge and address the risk that coronavirus can be transmitted in microscopically small droplets that are released into the air just by talking or breathing.

In an interview at the time, Haas, an environmental engineer at Drexel University, ticked off the precautions the experts were advocating: “Universal masking. Avoid crowds. Avoid confined spaces. Keep a physical distance. And for indoor spaces, improve ventilation.”

That, of course, was before COVID-19 vaccines began to loosen the pandemic’s grip on this region. But Haas remains cautious, at least for now.

“I have reservations about indoors in groups with no masking, even though I am fully vaccinated,” Haas said. “As case rates drop further and vaccine uptake rates increase, this will change.”

In buildings on the Drexel campus, “other than when I’m alone in my office, I am masked. I have been back to my office once or twice a week (taking SEPTA) since I became fully vaccinated in early April.”

Outdoors, Haas feels safe shedding his mask, especially in his Society Hill neighborhood, where vaccination rates are high. Still, he and his wife avoid crowds.

“We only have occasionally gone into stores, where we remain fully masked,” he said. “I am hoping by the time the city lifts the indoor mandate, we will be comfortable being in some of the indoor spaces we love.”

Reading Terminal Market, he added, is at the top of the list.

Mayssa Abuali, pediatrician at Einstein Medical Center

Mayssa Abuali’s biggest concern is how to help families with unvaccinated children under age 12 navigate this summer safely.

Abuali, a pediatrician at Einstein Medical Center with expertise in infectious diseases, said she is not currently masking her young children when outdoors.

“The risk of outdoor transmission is minuscule to both adults and children, and young healthy children are not at high risk for COVID-19 even when indoors,” she said.

Abuali also said she is comfortable unmasking young children indoors if the surrounding adults are vaccinated, such as in a recreational class with vaccine requirements for instructors, because studies have shown that young children are most likely to be infected from contact with sick adults and not other children.

She said she continues to wear a mask in local businesses that request masking “to make the owners and patrons feel comfortable.” But, she said, “I agree with the CDC that masking for vaccinated persons is not necessarily as they are not likely to transmit or catch infection.”

When it comes to summer travel, though, Abuali said she is still refraining from flying with her unvaccinated children because of the potential for poor ventilation on planes and variability of adult vaccination rates across the country.

“I plan to reassess the risk as more American adults are vaccinated and our [case] rates show consistent declines,” she said.

Jeffrey Duchin and Jeanne Marrazzo, Infectious Diseases Society of America

At a recent media briefing from the Infectious Diseases Society of America, Jeffrey Duchin acknowledged that the CDC’s updated messaging on mask-wearing was abrupt and confusing. Based on science that the vaccines work very well, it was meant to assure the vaccinated that they are safe both inside and outside without masks. But many quickly interpreted the guidance to mean that mask mandates should be lifted, said Duchin, who is health officer of public health for Seattle and King County, Wash.

Because unvaccinated people are still at risk, Duchin worried that lifting requirements too fast raises the risk of an increase in viral transmission. Public health officials, he said, need to take into account that vaccination rates vary by age group — rates are highest among older adults — and by neighborhood.

Transmission is still a risk in crowded indoor spaces. “Steps to improve ventilation and indoor air quality are especially important now,” he said.

Jeanne Marrazzo, director of the division of infectious diseases at the University of Alabama at Birmingham, said at the briefing that people who are fully vaccinated and in good physical health should feel “100% fine going anywhere without a mask” once transmission rates are low and vaccination rates are high. However, she said, about three million Americans are immunocompromised and we don’t know how well the vaccines protect them.

“People need to monitor what’s going on in their communities very closely and be prepared to pivot and adapt,” she said.

She said she will feel more comfortable when disease rates are very low and 80% of the population is vaccinated, goals she does not expect the United States to reach soon.

For her, masks may always have a role. She pointed to the drop in flu and other respiratory infections this year. “Masks are a pretty powerful weapon against respiratory illnesses,” she said. “I’m still wearing a mask when I go anyplace in public where I live because our vaccination rates are less than 50%.”