With coronavirus cases in the UK now at almost 30,000, fears about the spread of the virus are now widespread.

Studies have previously warned that smoking and vaping can increase your risk of catching the virus, and now one expert has warned that smoking cannabiscan also increase your risk.

Speaking to SF Weekly, Dr Stanton Glantz from the UCSF Centre for Tobacco Control Research and Education, said: “Smoking doesn’t cause the flu, vaping doesn’t cause the flu. But people who smoke or are exposed to secondhand smoke are more susceptible to getting sick.

“There’s not a lot of direct data on COVID. But there’s a ton of evidence that smoking and vaping depress immune function in your lungs.

“If you look at cannabis smoke and compare it to tobacco smoke, it’s not that different. You have THC instead of nicotine, but the immunosuppressive effects do not seem to be primarily because of nicotine.”

Unfortunately, there are yet to be any specific studies to assess the impact of smoking cannabis on coronavirus risk.

Dr Glantz added: “The amount of research we have around cannabis is very limited. And I think that’s a huge problem.”

Dr Glantz’s warning comes shortly after the Chief Medical Officer for England warned that smokers are more at risk from coronavirus.

Professor Chris Whitty said "if you are going to give up smoking, this is a very good moment to do it."

The medical expert stressed people who smoke should not go into self-isolation or behave differently.

But he said smokers face an "additional vulnerability" compared to other healthy people from respiratory illnesses. In general, he said, "they are more likely to get it and their immune system is less good."