LEGAL GROUPS, including the American Civil Liberties Union of Massachusetts, have made an urgent plea to the state’s highest court. “There are about 16,500 human beings in our prisons and jails,” they wrote in a court filing. “None of them have been sentenced to death. Yet, without aggressive and immediate intervention, COVID-19 will likely kill many of them.”

As any medical professional on the front lines of the current crisis will tell you, this is not hyperbole. If left unchecked, COVID-19 will wreak havoc on incarcerated people and correctional staff, as well as their families and the wider community. To flatten the curve, save lives, and alleviate stress on the state’s health care system, we are asking the Supreme Judicial Court to reduce jail and prison populations and safely release as many people as possible.

This is not just a matter of legal advocacy—it is a medical and public health necessity. To highlight this need, 14 leading experts in epidemiology, infectious diseases, public health, and health care for incarcerated people filed a letter to support the emergency petition. They warn that a refusal to reduce incarcerated populations “poses a grave threat to the lives and health of countless people” and that “the safest response is to release as many people as practicable to self-isolate, especially those who are vulnerable due to health or age.”

Much of the incarcerated population in Massachusetts is especially vulnerable to severe COVID-19. According to the letter from public health experts, people entering correctional facilities are often members of marginalized groups—people of color, poor people, disabled people, and LGBTQ people—that have long suffered the effects of health inequities in our society. As a result, incarcerated people are more likely to have the kinds of co-morbidities that put them at increased risk for severe COVID-19 that could require intensive care and potentially leading to death.

We know our most important tool to prevent this virus is frequent hand washing and physical distancing of at least six feet. But jails and prisons are congregant settings with limited access to basic hygiene products. Even at normal capacity, these correctional facilities do not have enough space to follow physical distancing protocols, and they often lack sufficient soap and sinks to allow people to wash their hands with any kind of regularity. With more than a dozen of Massachusetts jails and prisons filled to more than 100 percent capacity, these problems can quickly become a catastrophe.

While people can be confined to a prison, the same cannot be said of a virus. Massachusetts correctional facilities are full of people moving in and out every day: new inmates, correctional officers, attorneys, visiting families. Although you can restrict some of them, you can’t stop officers from changing shifts, cycling between their posts and their communities. Given this movement, it is very unlikely that this virus can be kept out, especially because we know asymptomatic carriers can spread the virus. By the time you identify an infected officer, it will likely be too late.

Because prison health care facilities are not equipped to treat someone with severe COVID-19, they will need to be transferred to a community hospital. An uncontrolled outbreak of COVID-19 would likely put an intolerable strain upon our local hospitals, at a time when they will be close to the breaking point and could lose their ability to care for other emergency matters, including heart attacks, strokes, and car accidents. By condemning people to suffer this pandemic within the walls of a prison, we in turn condemn our emergency workers and, ultimately, ourselves. We cannot afford to let political considerations blind us to the overwhelming consensus of the medical community: Wherever there are crowds of people, we must work to disperse them.

The US has the highest rate of incarceration in the world, and we would be foolish to think that we can’t afford to lower that number, even temporarily. We lock people up for countless reasons, both trivial and serious. Many if not most people who are incarcerated pose no threat to society. The virus, by contrast, is merciless, and it does not discriminate. It—not our fellow human beings—is the enemy.

Extraordinary times call for extraordinary measures. The federal government is failing—miserably—to handle this crisis. The state Legislature is unlikely to act in time. Now, we are asking the Supreme Judicial Court to help ensure the well-being and safety of incarcerated people, correctional officers, and all of our communities.

Dr. Josiah Rich is professor of medicine and epidemiology at Brown University. Carol Rose is the executive director of the ACLU of Massachusetts.