There are a lot of additives in cigarettes, some of which suppress symptoms of the damage smoking does to the lungs. So it's possible that it's not the nicotin

There are a lot of additives in cigarettes, some of which suppress symptoms of the damage smoking does to the lungs. So it's possible that it's not the nicotine at all. Should be easy to test by looking at data from people who had COVID-19 and were using nicotine patches at the time.