> For example, we thought that plain cloth masks were somewhat effective at stopping transmission, but now we know that they are not What links do you have sup

> For example, we thought that plain cloth masks were somewhat effective at stopping transmission, but now we know that they are not What links do you have supporting this?/Can you give more details? There is evidence regarding Omicron but as far as I'm aware that is it. Afaik masks were effective.