A heat recovery ventilator works fine in the winter. Its whole purpose is to introduce fresh air into the conditioned space while preheating it with the heat in the dirty exhaust air stream.
HRVs have been designed to exchange heat, and ERVs to exchange heat and moisture, but have either specifically been designed not to exchange virus particles? One wouldn't want to make any assumptions...
At least with heat recovery ventilators, the air streams do not mix at all. Unless the virus finds a way to penetrate the metal fins of the heat exchanger, it should be completely fine.
