How could it possibly affect your canvassing?
If he’s coughing while doing his canvassing speech?
If that were to be an issue he’d also have to have contracted COVID19.
Otherwise if that weren’t that case he wouldn’t be able to go shopping, down the pub, the library, to work, do the gardening, take the dog for a walk, go out for a walk, visit friends or family, go to the doctors bla bla bla......