the vast majority of viruses (yes, including influenza and covid) are not adapted to traveling significant distances. even among these viruses capable of spreading via aerosolization (which again, are a minority of viruses), the threat vector is person to person, or person to surface to person. the idea of someone outside, or even in another room, sneezing or coughing and the virus spreading via particles suspended in water droplets floating from the area surrounding the immediate vicinity of the cougher's mouth, through a ventilation system, and then into a new host, is anti-science magical thinking. the filtration system will likely never come into contact with a significant amount of viral particulates, if any at all. it does nothing.
United States