> So, to get closer to elimination, we also need a way to reduce the virions circulating in high density environments. During COVID the world experimented with various interventions like social distancing and personal protective equipment. But to reduce transmission durably for a large number of common respiratory viruses that are perennially circulating, we need solutions that are convenient and minimally disruptive.

We think the most promising category of products that accomplish these goals are those that remove pathogens from the air, particularly in high-density environments like offices, schools, and public transit. We’ll call these air cleaning technologies (ACTs) like air filtration and far-UVC antimicrobial light.

Sounds like a pretty big challenge to me... Ok, during Covid I read that airplane-style air conditioning with nozzles above each seat and used air pumped out at ground level was pretty good in making sure "your" air didn't get mixed up with your neighbor's (masks were still mandatory however on the few flights I took during that period). But how are you going to do the same in a packed subway train in, let's say, Tokyo or New York, at rush hour? That air conditioning unit would probably have to be as heavy as the train itself, and to the passengers it would feel like a hairdryer (on cold setting) blasting at them permanently from above...