The latest Covid report from Public Health Scotland has gone back to adding data normally after last week where a backlog was added without any kind of helpful differentiation between the normal data and the one-off additions. This means we can resume our effort to get a rough estimate of how well the vaccines are preventing death.
Here’s the data so far presented by week.
In the bottom right table I have ignored the week July 16th-22nd, when the backlog was added, to get two weeks’ worth of data covering July 9th-15th and July 23rd-29th. Focusing just on the over-50s (for which vaccination rates are now stable), we can see that there were 14 deaths in the unvaccinated added in those two weeks and 60 deaths in the double vaccinated. Using our rough estimates from last time of vaccine coverage in the over-50s of 7% unvaccinated and 91% double vaccinated, this gives a (roughly estimated) vaccine effectiveness against death in those two weeks of 67% (1-((60/91%)/(14/7%)). This is up from 46% from one week’s data last time, and heading closer to the estimate from PHE data of 77%. This is perfectly respectable and will (if correct) be contributing to reducing the death toll from COVID-19, but is notably much lower than the up-to-99% effectiveness against death currently estimated by PHE in their official reports.
Another point of note from the latest PHS report is that it shows that the majority of both new positive cases and hospital admissions are in vaccinated people. According to the report, in the four weeks up to August 6th, “48.1% of COVID-19 positive PCR cases were in unvaccinated individuals” and “46.8% of COVID-19 related acute hospital admissions were in unvaccinated individuals”. There are confounders of age and the proportion of the population vaccinated, of course, but even so this shows that any attempt to claim that the majority of current infections or hospitalisations are in unvaccinated people is misleading.
The growing share of the vaccinated in new infections and hospitalisations also appears to be confirmation of the phenomenon noted from PHE data earlier this week, where infections in the unvaccinated peaked and declined ahead of those in the vaccinated. This phenomenon warrants further investigation.