How China’s fake news machine is rewriting the history of Covid-19, even as the pandemic unfolds

Doctor's Note: Why Are Smokers More Vulnerable To Coronavirus?

A doctor explains why smokers are more likely to contract respiratory illnesses.

Smoking is one of the leading causes of death in the world, killing more than eight million people a year, according to the World Health Organization (WHO). Now, it is thought that smoking may also make people more vulnerable to developing serious complications if they catch coronavirus.

In the United Kingdom, the health secretary, Matt Hancock, has said: "It is abundantly clear from the research into previous coronaviruses that smoking makes the impact of a coronavirus worse."

We do know that smokers contract more respiratory illnesses, including the common cold which is also a coronavirus, than non-smokers. They also tend to have a higher rate of bacterial pneumonia and tuberculosis. During the Middle Eastern Respiratory Syndrome (MERS) outbreak in 2012, smokers were found to be more likely to die than non-smokers if they caught the virus. 

Furthermore, smokers are twice as likely as non smokers to contract influenza and have more severe symptoms. 

However, the evidence has been less clear when it comes to the relationship between smoking and COVID-19, the disease caused by the novel coronavirus, specifically.

There have been some concerns that smokers are more likely to contract the virus because of the action of putting your hand to your mouth or using unwashed, contaminated hands to roll cigarettes which can increase the transmission of the virus from hand to mouth.

Some smoking products such as water pipes can involve sharing mouthpieces and hoses, which could also facilitate the transmission of COVID-19.

However, in a study of China's outbreak in the New England Journal of Medicine, it was found that fewer than 15 percent of the patients with COVID-19 were current or former smokers. Given the number of smokers in China - roughly one-fifth of the population - this might imply that smokers are not necessarily at a higher risk of catching it.

There is, however, evidence to suggest that smoking increases the severity of the virus if you catch it. The largest study looking at 1,099 patients in China, found that smokers were 1.4 times as likely to have severe symptoms and 2.4 times more likely to be admitted to an Intensive Care Unit (ICU), need ventilation or die compared with non-smokers who caught coronavirus.

A further small study of 78 people with COVID-19 also found a statistically significant higher proportion of smokers in the group whose condition adversely progressed compared with the group that showed improvement or stabilisation.