A vast coalition of professional medical groups on Monday called for mandatory COVID-19 vaccination of all health-care workers, while the U.S. Department of Veterans Affairs announced that its 115,000 frontline medical workers have eight weeks to get the shots or risk losing their jobs.

The nation’s health-care workers, who have witnessed the devastation of COVID-19 firsthand, were prioritized for immunization in December, yet surveys show about a quarter of them — more than a third in long-term care facilities — have so far refused to roll up their sleeves. At this point, with the highly contagious delta variant driving a new surge in infections, unvaccinated workers are ignoring their ethical responsibility, the coalition concluded.

Mandating vaccination “is the logical fulfillment of the ethical commitment of all health care workers to put patients as well as residents of long-term care facilities first and take all steps necessary to ensure their health and well-being,” said the joint statement from 56 health-care associations, including the American Medical Association.

The majority of the nation’s health systems and nursing homes, including those in Pennsylvania and New Jersey, have been reluctant to take a tough line on COVID-19 vaccination, even though flu vaccination mandates are standard in the industry. An oft-cited reason for the inconsistency is that COVID-19 vaccines have emergency authorization and are not yet fully approved by regulators. But some public health experts say hospital administrators just don’t want the bother of disgruntled employees.

This spring, the University of Pennsylvania Health System and the Houston Methodist Hospital system were among the first in the nation to adopt mandates; Methodist even successfully defended its policy against a lawsuit.

Earlier this month, Marlton, N.J.-based Virtua Health announced its 14,000-member workforce must be vaccinated by Sept. 15.

And on Monday, Jefferson Health System spokesperson John Brand said employees have been told that a mandate is coming, although the timing is still under discussion. Jefferson’s requirement will affect employees at 14 facilities, including Abington Hospital, Main Line Health hospitals, and Einstein Healthcare Network.

But most systems are leaving vaccination up to employees and relying on less effective precautions such as masking. Temple Health, the University of Pittsburgh Medical Center system, and Reading-based Tower Health said they are monitoring COVID-19 trends and recommendations, but have no plans for a vaccine mandate.

Camden-based Cooper University Health Care and Wilmington-based ChristianaCare have no mandates and did not offer comment in time for publication.

The three vaccines authorized for emergency use in the U.S. have proven to be remarkably protective and safe. But the delta variant, now dominant in much of the country, is posing renewed challenges. The shots are still largely effective at warding off delta, and “breakthrough” infections are rare and usually not severe. Still, experts are considering whether booster shots will be needed.

Health workers who have shunned vaccination generally portray their decision as a matter of personal liberty and choice — cherished ideals in American culture.

But when that choice endangers patients, it is not justifiable, mandate supporters agree. The health-care community has made strides in preventing hospital-acquired infections, which sicken 1.7 million patients each year, including 99,000 who die as a result, according to the U.S. Centers for Disease Control and Prevention.

The lagging COVID-19 vaccination rates among health-care workers is an unnecessary setback.

“We’re mandating vaccines for Title 38 employees because it’s the best way to keep Veterans safe, especially as the Delta variant spreads across the country,” Veterans Affairs Secretary Denis McDonough said on Monday of his agency’s health-care workers. “Whenever a Veteran or VA employee sets foot in a VA facility, they deserve to know that we have done everything in our power to protect them from COVID-19. With this mandate, we can once again make — and keep — that fundamental promise.”