When compared to folks with COVID-19 who didn't use e-cigarettes, those who did were more likely to report chest pain, chills, headaches, muscle aches, nausea, vomiting, diarrhea and the loss of smell or taste.

What's more, folks who vaped and smoked tobacco reported higher rates of labored breathing and more emergency department visits when they contracted COVID-19, the new study findings showed.

The study provides another reason to quit vaping or smoking. Or better yet, never start, say experts not involved in the new study.

"The list of heart and lung diseases and conditions associated with smoking and vaping is long, and the stakes are even higher now that we are living through a pandemic of respiratory infection," said Dr. Len Horovitz, a pulmonologist at Lenox Hill Hospital in New York City.

"Vaping causes inflammation in the lungs, and inflammation is a breeding ground for any infection or virus," said Horovitz. "Vaping may worsen the systemic inflammation associated with COVID-19, causing an increase in symptoms such as fever, myalgia [muscle aches and pains], fatigue and headache."

For the study, researchers led by Dr. David McFadden, an internist at the Mayo Clinic in Rochester, Minn., interviewed close to 290 COVID-positive vapers aged 18 and older, and compared their symptoms to those of similar-aged people who had COVID-19 but didn't vape.

The new study wasn't designed to find out if people who vape or smoke tobacco have a higher chance of catching COVID-19 in the first place, and the jury is still out on that, the researchers noted. This study was able to show that people who smoke and/or use e-cigarettes are more likely to experience a greater number of COVID-19 symptoms when they do become infected.

This makes sense to Dr. Neil Schachter. He's a professor of pulmonary and community medicine and medical director of pulmonary rehabilitation at Mount Sinai Medical Center in New York City.

"Smoking or vaping causes damage to the airways and lungs themselves, and we know that underlying conditions and, in particular, respiratory conditions are significant factors in whether you become very sick or die from COVID-19," Schachter said.

"Cigarette smoke and probably vaping increase the number of angiotensin-converting enzyme 2 [ACE 2] receptors on airway cells, and may make them more susceptible to being infected by the coronavirus," he said, because COVID-19 locks into ACE 2 receptors on cells for entry into the body.

"You would likely have more severe disease, too, because you have more of these viruses entering your cells," Schachter added.

This study didn't include tweens or teens under 18, many of whom may vape, but the findings likely extend to that age group as well, he noted.

There are more ways to quit smoking today than ever before, including nicotine replacement products such as the patch, gum, lozenges and inhaling devices. Schachter said that his favorite is "the lozenge, because it's something you can pop into your mouth whenever you have a nicotine craving, and it also takes care of the oral component of smoking."

Nicotine patches can also be really helpful, he said. "There are also online and in-person support groups that are valuable," Schachter advised.