More than 87,100 federal executive branch employees who work in Pennsylvania and New Jersey will soon be required to be vaccinated against the coronavirus as part of the mandate announced Wednesday by President Joe Biden.

Also included in the mandate are federal contractors and health-care workers, as well as employees of any business with 100 or more workers, who must be tested weekly if they decline vaccination.

It’s a move that has the potential to boost the vaccination rate in the Philadelphia region, and across the country, at a critical time — when students are returning to school, some workers are returning to offices, and the highly transmissible delta variant is circulating, devastating other parts of the country.

“I’m grateful that the Biden administration is taking strong steps to protect the public,” Pennsylvania Gov. Tom Wolf said in a statement. “I strongly support the efforts at the federal level to prioritize vaccinations, which further support my administration’s efforts to stop the spread of COVID-19 — efforts that are working.”

In recent days, cases and hospitalizations have appeared to level off in the area, which experts attribute in part to the region’s relatively high vaccination rates. About 70% of Pennsylvanians and New Jerseyans of all ages have received at least one dose of a coronavirus vaccine, according to the New York Times, while 56% of Pennsylvanians and 62% of New Jerseyans are fully vaccinated. Those numbers far exceed those in many other states, but experts say an even higher full vaccination rate — perhaps above 80% — is needed for widespread protection. And mandates, they say, have been proven to work.

“I would expect this to add a nontrivial number of new people to the pool of the vaccinated as larger employers start requiring the COVID-19 vaccine,” said Katherine Ognyanova, an associate professor of communication at Rutgers University and a co-lead on the COVID States Project, a nationwide research initiative that has found the majority of people support mandates.

“No doubt, the new requirements will cause a backlash among the most vaccine resistant groups, especially those on the ideological right who would see this as government overreach,” she added. She noted that the project’s research had found men, older people, people of color, urban residents, those with higher education and income, and Democrats strongly support mandates, while only half of Republicans do. But, “I still expect this will push a considerable number of vaccine-hesitant Americans toward vaccination.”

Simon Haeder, an assistant professor of public policy at Pennsylvania State University who has also researched mandates, said he expects the federal mandate’s largest impact to be in empowering more private businesses to follow suit and require shots with few exceptions.

“The way to think about this is not the direct effect of the mandate,” he said. “It’s more a precedent, leading-by-example kind of thing.”

There could be some bumps on the road to setting that precedent — potential legal challenges, Haeder said, as well as perhaps some early retirements or resignations of workers who don’t want to get shots.

» READ MORE: Philly-area COVID-19 cases are leveling off, but health community is ‘bracing for an uptick’ heading into fall

These challenges will be similar to those faced by employers and agencies that have already instituted mandates.

“We’re in this labor shortage situation, which is complicating these decisions for a lot of companies,” Haeder said. “I think when you’re going to get companies to really move is when their bottom line is getting affected” from virus outbreaks that cause employees to miss work when they get sick, quarantine from exposure, are hospitalized, or even die.

The U.S. Department of Veterans Affairs may provide a preview of what other federal entities and businesses can expect. In July, it said it would require all employees to get vaccinated by mid-October. Unvaccinated employees, including those with an approved medical or religious exemptions, must get tested for COVID-19 weekly.

The Corporal Michael J. Crescenz VA Medical Center in Philadelphia saw a small bump in vaccination following the announcement, but a large portion of the medical center’s roughly 3,500 employees were already vaccinated, said John Kelly, the facility’s chief of staff, who oversees clinical operations. To date, about 75% of employees are fully vaccinated, with only a small number seeking a medical or religious exemption.

The U.S. Centers for Disease Control and Protection has compiled a list of medical conditions for which a medical exemption can be granted. But religious exemptions are more vague, which makes granting — or denying — a request challenging.

”It’s sort of an honor system,” Kelly said. The remaining 25% of employees includes people who may have gotten vaccinated but not yet reported it, have only gotten their first dose, or are hesitant.

To address vaccine hesitancy, medical center leadership has been holding regular town hall meetings to answer questions and inviting frontline health workers and department leaders to share their experiences getting vaccinated. Personal conversations with people who have concerns about the vaccine have been the most effective approach for changing minds.

» READ MORE: Some people’s minds are changing about the coronavirus vaccine. Here’s how doctors persuade them.

”What we want is for veterans and workers alike to want the vaccine,” said Matthew Garin, who leads the medical center’s COVID-19 task force.

Medical worker unions that have opposed vaccine mandates have warned of potential staff shortages, as people who do not want to get vaccinated or submit to routine testing seek employment elsewhere.

Garin said staffing “is going to be a concern if people leave en masse because of the mandate,” but that the VA must press forward with vaccination efforts to ensure a safe environment for staff and patients.

”We have a moral and ethical responsibility to protect our patients and each other,” Garin said. “When the system breaks down because of illness, everyone suffers.”

This fall and winter, when cases are expected to rise, “the balance [in the minds of employers] is going to tilt more toward the impact of COVID than the worry about people resigning,” said Penn State’s Haeder.

And mass resignations are unlikely even when mandates receive pushback. “At the end of the day how many people are going to give up a well paying job with benefits?” Haeder said, especially as more and more employers require vaccines, leaving fewer alternative jobs.

» READ MORE: Should you laminate your vaccination card? What if you lose it? Here are the dos and don’ts.

More states and counties are announcing stricter requirements, too.

Gov. Wolf has mandated vaccines for health-care workers at state-run facilities. New Jersey Gov. Phil Murphy has required that state employees, teachers, and health and congregate-care workers be vaccinated or undergo weekly testing.

Bucks County, which a spokesperson said supports the federal mandate, recently instituted a similar mandate for its employees. Delaware County is requiring vaccinations for county health and custodial care workers, including at Fair Acres, the county’s skilled nursing facility, a spokesperson said, but was still deciding whether to require the shots for all staff as of Thursday.

Through her research with the COVID States Project, Ognyanova has found that the more employers that require shots, and the more people who get them, the stronger the domino effect.

“Seeing a larger number of their social contacts or people in their community get vaccinated could potentially be compelling for the vaccine hesitant,” she said. “Similarly, once a large number of businesses start requiring vaccines, this may be something that even employers unaffected by the mandate may start requiring, as it becomes a more standard and accepted practice to do so.”