Thanks, [2] is interesting. Sadly lacking much information on the transmissibility of the delta variant, which is the dominant strain in most (?) western countr

Thanks, [2] is interesting. Sadly lacking much information on the transmissibility of the delta variant, which is the dominant strain in most (?) western countries. Such information would tell us whether achieving herd immunity without direct infection from SARS-CoV-2 requires continual application of boosters forever (i.e. for each seasonal variant). I say this because there is evidence from other respiratory viruses that, after having transitioned from animal to human, they typically mutate to become more transmissible but less deadly, which we normally deal with by letting sweep through the country without mass vaccination (only for the vulnerable).