I think the switch to 8 weeks was at least in part driven by the different characteristics of the Delta variant. Whereas for the previous variants the two doses of the vaccine did something like 70% and 90% protection, for the Delta variant it’s more like 35% and 80% (vague hand wavey numbers). So now there is similar marginal benefit to getting second doses into people, and because the roll out has been by age category, getting (say) 60-year olds from 1 dose to 2 might well be more beneficial than getting 20-year olds from 0 to 1.
It’s quite unclear to me why they not just switch the spike protein to the one of the Delta variant if that’s the main reason for chaing how they vaccinate.
I think the switch to 8 weeks was at least in part driven by the different characteristics of the Delta variant. Whereas for the previous variants the two doses of the vaccine did something like 70% and 90% protection, for the Delta variant it’s more like 35% and 80% (vague hand wavey numbers). So now there is similar marginal benefit to getting second doses into people, and because the roll out has been by age category, getting (say) 60-year olds from 1 dose to 2 might well be more beneficial than getting 20-year olds from 0 to 1.
It’s quite unclear to me why they not just switch the spike protein to the one of the Delta variant if that’s the main reason for chaing how they vaccinate.