[user104658]

In all honesty though the science behind mask wearing is still very flimsy. That's inevitable really, it wasn't being properly looked at until less than 6 months ago, and that simply isn't anywhere near long enough for any really robust research to have been carried out. Previous "non-Covid" studies into mask wearing and the effect on the spread of illness has shown that it has little if any significant effect - BUT they have also shown that it doesn't do any harm. We're all sort of operating on "best guess" scenarios with it at the moment... and my take is that, if we know it's unlikely to cause any harm, and the effectiveness of how much good it does is "an unknown", we might as well err on the side of caution and wear them .

The data will be available one day and we'll have some pretty robust stats on how effective it was (if at all). For now, there's no reason NOT to.