Canada's Health Agency Threw Out 5.4 Million N95 Masks Shortly Before Pandemic: Audit"Masking helps prevent the spread of common respiratory viruses such as influenza, COVID-19, RSV and a variety of other respiratory viruses that circulate in the cooler months," Hota said. "Influenza usually picks up in November, peaks in December/January and then comes back down by March or April. RSV is expected to start rising a little earlier than influenza but has a similar duration of peak activity."