Tobacco and marijuana products damage lungs, where the virus does its harm. Health officials are urging people to quit, and temporary sales bans are even being discussed.

Anxious times — like a pandemic — can lead to unhealthy but self-soothing habits, whether it’s reaching for a bag of potato chips, more chocolate or another glass of wine. But some stress-reducing behaviors are alarming to medical experts right now — namely vaping and smoking of tobacco or marijuana.

Because the coronavirus attacks the lungs, this is exactly the moment, they say, when people should be tapering — or better yet, stopping — their use of such products, not escalating them.

”Quitting during this pandemic could not only save your life, but by preventing the need for your treatment in a hospital, you might also save someone else’s life,” said Dr. Jonathan Winickoff, director of pediatric research at the Tobacco Research and Treatment Center at Massachusetts General Hospital.How to Quit Smoking and Vaping During the Coronavirus PandemicPeople who smoke and vape may be at greater risk for Covid-19, but quitting is hard, especially now. The good news: There are a lot of helpful resources. April 9, 2020

On Thursday, Dr. Winickoff joined the Massachusetts attorney general, Maura Healey, to issue an advisory alerting the public and particularly young people that smoking and vaping can also exacerbate the risks of spreading Covid-19.

“You bring this device or cigarette to your mouth to inhale and you do so repeatedly,” explained Dr. Winickoff, who is also a professor at Harvard Medical School. “You touch the cartridge. You put it next to your face. You are spreading whatever is in your hand into your body. At the same time, many of my patients who smoke or vape have increased coughing or expectorating. And that’s a recipe for increased spread.”

Studies already amply show that cigarette smoking weakens the immune system and compromises lung function. Research into the health effects of vaping is limited because the devices are relatively new, but studies suggest that e-cigarettes may cause inflammation in the airways and lungs.

Flavored tobacco products, which teenagers and young adults find particularly alluring, can exacerbate lung infections, studies have found. Smokers and vapers, then, may be more susceptible to coronavirus infection, the Massachusetts advisory emphasizes, and once infected, such patients might also have a tougher time resisting an attack of Covid-19. Studies in mice have shown that vape-exposed mice are more susceptible to viral and bacterial infections, noted Robert Tarran, a professor of cell biology and physiology at the University of North Carolina.

Some people have questioned whether unexpectedly high numbers of younger people who have become seriously ill with Covid-19 are connected in some way with their predilection for vaping and marijuana.

“I am a firm believer that one plus one equals two. Until I have the evidence to believe otherwise, I believe it is critically important for us to help people quit inhaling anything into their lungs that could be causing any type of inflammation, as the coronavirus will only find an inviting environment otherwise,” said Dr. Carolyn Dresler, a former associate director of medical and health sciences for the Center for Tobacco Products at the Food and Drug Administration, during a webinar last week for Action on Smoking and Health, an international nonprofit group.

A recent study in the New England Journal of Medicine found that Chinese coronavirus patients who smoked were more than twice as likely as those who didn’t to have severe infections from Covid-19. And smoking has been identified as a factor in patients who became ill in 2012 with MERS, another coronavirus.

Another signal points to the vulnerability of smokers to this coronavirus. The virus seems to attack the body by attaching to a binding receptor called angiotensin-converting enzyme-2, or ACE-2. Tobacco use may increase the expression of ACE-2. That is why doctors and researchers speculate that smokers may become infected with more copies of the virus than other patients.

About 34 million adult Americans smoke cigarettes, according to recent data, and some five million middle- and high-school students report having vaped nicotine and marijuana products.

A frightening outbreak of life-threatening lung illnesses tied to vaping last summer was eventually tied to vaping marijuana oils that contained the additive vitamin E acetate. But doctors say at least 15 percent of the patients reported having vaped only nicotine products.

Dr. Winickoff, a pediatrician, said that prudence about marijuana products was also advisable: “Inhaling combusted or vaped cannabis products can damage lung cells, may increase viral replication, and does affect the ability to fight off infection,” he said.

“Clean air is what the lungs should be inhaling, especially during a global pandemic.”

Last month, the New York State Academy of Family Physicians called for a ban on sales of tobacco and e-cigarettes in the state during the pandemic. Already smoke shops are being shut down in many states because they are not deemed to be “essential” businesses. But some public health officials note that other retailers that sell cigarettes and vaping devices, such as gas stations and grocery stores, are still permitted to do so.

In defending such bans, public health experts say that behaviors associated with these products can provoke the spread of the virus. Wafting smoke and vapor may contain virus particles. Tobacco chewers tend to spit on the street. People often share e-cigarettes and cigarettes. And in using the products, consumers touch their faces frequently, increasing both their chances of becoming infected and then transmitting the virus.

One pushback to such bans, similar to that echoed among decisions to categorize wine and spirits as “essential” and permit their sales, is that so many people are addicted to cigarettes and e-cigarettes that they would be immediately thrown into the miseries of withdrawal.

But Dr. Winickoff of Harvard noted that it is nicotine that people are addicted to, not cigarettes or e-cigarettes per se.

“Use the nicotine patch for a baseline level of nicotine and then add in nicotine gum or lozenge for breakthrough cravings,” he said. “That’s the best way to use those products. Combining them will quadruple your chances of success.”

Dr. Alicia Casey, who directs the pulmonary vaping program at Boston Children’s Hospital, noted that one obstacle that had prevented her teenage patients from quitting was the omnipresence of the devices at school and parties. She had hoped that the enforced social distancing would help them quit.

“But I do often see that they’re more anxious now, and they’re vaping more frequently,” she said. “If parents notice that happening, they should speak with their kids about the risks of Covid-19 and other pulmonary complications to vapers.”

“I had a couple of teenagers this winter who had more trouble with influenza than they should have,” Dr. Casey continued. “Since Covid-19 can be similar to a severe influenza, I worry about those underlying lung issues from vaping.”

Sheila Kaplan contributed reporting.