Statistics in the Pfizer Data – how good do they show the vaccine to be? I never found any virologist who predicted we would have a vaccine that was more than than 70% effective. To have a vaccine that is likely about 95% effective for people 18-64 is nothing short of a medical miracle: we really lucked out.
However, when you look at the key statistical table (“Table 8: Subgroup Analyses of Second Primary Endpoint: First COVID-19 Occurrence From 7 Days After Dose 2, by Subgroup) things get murkier. More precisely, what one sees is exactly what I thought would happen, the signal becomes really bad for people over 65 and completely useless for people over 75. ...
My friends who think about these questions feel pretty strongly that while the vaccine will likely be less effective in people over 65 than it is in younger people, the dropoff won’t be great enough to make a big difference. For example, if it is 20-25% less effective in these age groups (which they think is the worst case scenario), you still get a vaccine that is roughly between 70% and 75% effective – which is still pretty darn good.
Still I wish they had enrolled enough people >65 to have a better signal!
