"Nicotine may inhibit the penetration and spread of the virus and have a prophylactic effect in COVID-19 infection."

"Finally, the nicotine patches may protect people in hight-risk areas/periods until they are vaccinated (if they accept it and are eligible for it) and in the post-vaccination weeks necessary for the effectiveness of the vaccine,which reinforces the importance of evaluating this alternative prevention strategy, in the context of the arrival of vaccines"

[link to clinicaltrials.gov (secure)]