I read an article a couple of days back about Hong Kong airport testing a new cabin, rather like a large telephone box/smoker's cabin where the passenger walks in and within the closed atmosphere is sanitised of all external bacteria and virus'. This doesn't seem to have any effect on internal maladies, but by wearing a mask the passenger would be 'clean' for the pre-flight and flight segments of travel..This, or similar might make the risk lower and therefore allow somewhat normal seating configurations on aircraft and so on