There is some excellent information from the Ontario Tobacco Research Unit in the following PDF. A couple of things that we want to draw attention to are:
Risk of Hand-to-Mouth Virus Transmission
Smoking and vaping involve frequent contact between fingers and lips. This increases the possibility of transmission of virus from hand to mouth. In some cases, smoking and vaping involve the sharing of cigarette and e-cigarette products and mouth pieces. Again, this could facilitate the transmission of COVID-19 in public and social settings.
Risk from Reduced Lung Capacity
COVID-19 is a lung illness that can cause patients to experience mild to severe lung complications. Pre-existing lung disease or reduced lung capacity may greatly increase risk of serious illness. Activities like smoking and vaping that reduce the ability of the body to use oxygen properly could put patients at higher risk of COVID-19 and other serious lung conditions. More research is needed and new evidence is emerging.
Please be sure to read the full PDF for all the information they have put together.