Early in the pandemic, tobacco researchers wondered how smoking impacted COVID-19. Years of evidence suggest that smoking worsens respiratory infections, and COVID-19 is no exception. One analysis, which looked at 19 peer-reviewed studies, found that people who smoked were nearly two times more likely to have negative outcomes from COVID-19. The CDC also determined that current and former smokers are at an increased risk for severe disease.

Researchers are still looking for definitive answers as to why or how smoking could increase risk for infection and lead to more severe COVID-19. Let’s consider what we know:

1. Cigarette smoke weakens the immune system

The Surgeon General’s 2014 report states that smoking compromises the immune system. When smoke enters the lungs, it damages immune cells, which make them less effective when trying to fight off viruses and bacteria. A weak immune system makes it harder for someone to protect themselves against infection and increases the chances of getting sick.

2. Smoking damages the respiratory system

In addition to harming immune cells in the lungs, smoking can also hurt the airways and small air sacs called alveoli in the lungs. Over time, this damage can result in lung disease, like chronic obstructive pulmonary disease (COPD), emphysema, and chronic bronchitis.

3. Long-term smoking can cause other chronic diseases that increase severity of infections

Smoking can cause disease throughout the body, not just in the lungs. Evidence shows that tobacco can cause cancer almost anywhere and harm nearly every organ. Serious heart conditions, obesity, diabetes, kidney disease, and many others are just some of the diseases that smoking can cause. These are all included in the CDC’s list of conditions that are at an increased risk for severe illness from COVID-19.

4. Smoking requires behaviors that conflict with current public health recommendations

By now, we’re familiar with the public health advice and mandates to stand six feet from others, wash hands regularly, wear masks, and avoid touching our faces. Smoking inherently violates some of these: in order to smoke a cigarette (or vape), someone must remove their mask and bring their hands to their mouth. Exhaled cigarette smoke may also carry coronavirus and potentially infect people standing nearby.

If you smoke or vape, make sure to do so outside and away from others, and wash your hands afterwards to avoid spreading disease.

There is no better time to quit.

Most health experts agree that smoking likely increases the risk of severe COVID-19 disease and may even contribute to disease transmission. Quitting tobacco is one way to protect yourself from worse COVID-19 outcomes. We also know that quitting is really hard, especially during a stressful global pandemic. If you or someone you live with needs support, there is help.

Originally posted December 12, 2020