NEW YORK (BLOOMBERG) - The US Food and Drug Administration made a second revision on its stance about the risks of Covid-19 and nicotine, saying that cigarettes also increase the chances of catching the virus that causes the disease.

"People who smoke cigarettes may be at increased risk of infection with the virus that causes Covid-19, and may have worse outcomes from Covid-19," the agency said in an emailed response to a question from Bloomberg News.

Earlier this month, the FDA had said that smokers may have worse outcomes from Covid-19, but had not been explicit about whether that included their chances of catching the virus in the first place.

The clarification comes as researchers and regulators race to study the new virus.

There are nearly 2.5 million confirmed cases and more than 171,000 deaths worldwide from Covid-19.

The world's estimated 1.1 billion people who smoke and 41 million people who vape have so far gotten varying guidance on the virus' potential threat from public health agencies.

With a disease that has only been studied for a few months, regulators and researchers have looked to old data on how cigarette smoking effects those with the flu, bronchitis and pneumonia.

They are also pressing ahead on new studies on vaping, which has not been around as long as smoking.

The FDA noted in its April 14 statement that cigarette smoking "causes heart and lung diseases, suppresses the immune system, and increases the risk of respiratory infections".

In its March 27 statement on the risks, the FDA had said that vaping and smoking only posed a higher risk for the coronavirus in people who had underlying conditions.

Some groups have said vaping may be safer than smoking.

The FDA said in its prior statement that the effects of vaping on Covid-19 are unknown, while cautioning that it exposes the lungs to toxic chemicals.