Public Health England yesterday released their latest
technical briefing on the variants of concern,
number 20, and it has some illuminating data.
It provides us with the infection, hospitalisation and death rates for the Delta variant, broken down by vaccination status and age. This allows us to do a calculation of the real-world vaccine effectiveness in the over-50s during the Delta surge, albeit a rough one without any adjustments.
The latest report has data up to August 2nd. If we substract from these values the data in
Briefing 17 (up to June 21st) then we get the data covering the period June 22nd to August 2nd, which broadly corresponds to the bulk of the Delta surge in the U.K. The vaccine rollout to the over-50s was basically complete by this point, having stabilised
according to PHE at around 88% double vaccinated and 10% unvaccinated (the other two per cent remaining single vaccinated, perhaps due to a bad reaction to the first dose).
In this period the PHE data tells us there were 2,464 Delta cases in the unvaccinated over-50s and 17,926 in the fully vaccinated over-50s. From this we can estimate the vaccine effectiveness against infection in the over-50s during the Delta surge as 17% (1-[(17,926/88%)/(2,464/10%)]). This confirms using additional data the estimate I made
last week.
Comment: Harassment wasn't the only thing DeRosa helped cover up: