Yesterday I wrote about the new data from Public Health England that allows us to make a (rough) calculation of vaccine efficacy during the Delta surge. Using data from technical briefings 17 and 20 I calculated that vaccine efficacy against infection with the Delta variant in the over-50s was a disappointing 17%. Vaccine efficacy against mortality was a better (if lower than expected) 77%.
The Daily Expose also published a piece looking at the new PHE data and argued that it showed vaccination was actually increasing the risk of hospitalisation and death. Their analysis did not break the results down by age, however, and so did not take into account that most of the infections are in the young, who are less vaccinated, and most of the deaths are in the old, who are much more vaccinated. That’s why my analysis focused on the over-50s, and when you do that you find the vaccines reduced mortality during the Delta surge in that age group by around 77%.
The Daily Expose article helpfully drew attention to the fact that in a recently published document, the Government advisers on SAGE themselves appear to admit that the vaccines do not prevent infection and transmission. In paragraph eight, they write:
While we feel that current vaccines are excellent for reducing the risk of hospital admission and disease, we propose that research be focused on vaccines that also induce high and durable levels of mucosal immunity in order to reduce infection of and transmission from vaccinated individuals. This could also reduce the possibility of variant selection in vaccinated individuals.
This being the case, why is SAGE not advising the Government to cease all aspects of the vaccination programme based on the idea of reducing transmission and protecting others (vaccine passports, the coercion of young people, vaccination of children and so on) as its members clearly don’t believe that these things are backed up by sound scientific evidence?
The Daily Expose article also highlights that there is another way of using the data in the PHE report to calculate the vaccine effectiveness against death. This is by calculating the case fatality rates (CFRs) in the vaccinated and unvaccinated groups respectively and taking the ratio.
Doing this for the over-50s, between June 22nd and August 2nd there were 339 deaths from 17,926 cases in the double vaccinated, giving a CFR of 1.9%, and 167 deaths from 2,464 cases in the unvaccinated, giving a CFR of 6.8%. One minus the ratio of these gives a vaccine effectiveness against death of 72% (1-(1.9%/6.8%)). Unlike the figure I calculated yesterday using population vaccination coverage, this is the vaccine effectiveness against death once infected, so doesn’t include any protection the vaccines provide against infection in the first place, meaning it is not surprising that it is lower. That it is not much lower is a further indication that the vaccines do little to prevent infection.
Because with this method we don’t need to worry about vaccination coverage in the population, we don’t need to restrict ourselves to the period June 22nd to August 2nd, which I selected because it was when the vaccination programme in the over-50s was basically complete. This means we can use all the Delta cases up to August 2nd as found in technical briefing 20. Again, for the over-50s, up to August 2nd there were 389 deaths from 21,472 cases in the double vaccinated, giving a CFR of 1.8%, and 205 deaths from 3,440 cases, giving a CFR of 6%. One minus the ratio of these gives a vaccine effectiveness against death (once infected) of 70%. So vaccine effectiveness against death in the over-50s rose slightly during the recent surge.
We can also use this method for the under-50s. Up to August 2nd there were 13 deaths from 25,536 cases in the double vaccinated, giving a CFR of 0.05%, and 48 deaths from 147,612 cases in the unvaccinated, giving a CFR of 0.03%. Strikingly, the CFR in the vaccinated here is higher than in the unvaccinated. In fact, it is 57% higher, meaning the vaccine effectiveness is negative 57%, i.e., in the under-50s the vaccine increases the risk of death once infected by 57%. This is in line with the Daily Expose‘s report, albeit the effect is found only in the younger population.
One caveat is that this doesn’t allow for any protection the vaccine might offer against infection, which may be higher in the under-50s (I haven’t attempted to calculate this as the vaccine coverage in that age group is constantly rising meaning I can’t pin down a figure). But even so, the fact that the case fatality rate among the vaccinated under-50s is 57% higher than among the unvaccinated under-50s is not just disappointing, it is alarming.
It’s worth bearing in mind that we are dealing with very small numbers here. There were only 61 deaths in these two groups (double vaccinated and unvaccinated under-50s) and only 13 of them were in the double vaccinated. One possible explanation is that these 13 deaths are highly vulnerable people who were vaccinated to try to protect them, while the CFR in the unvaccinated was driven down by the high infection rate among socially active young people. A more reassuring statistic, using data from the same report, is that the vaccine effectiveness against A&E attendance (once infected) among under-50s is 35%, and against an overnight hospital stay is 43%. These are not exactly stunning results, but do at least indicate a positive effect. Interestingly, the same statistics for the over-50s are a vaccine effectiveness against A&E attendance once infected of 71% and against an overnight hospital stay of 73%, indicating again an unexpectedly higher efficacy in the older population. Is this an artefact of higher risk younger people being vaccinated first?
Since, then, the disturbing statistic arises from just 13 deaths, perhaps the most sensible course of action would be for PHE to investigate these 13 deaths and publish a report assessing what role if any the vaccine may have played in them. More generally, given that the number of Covid deaths in vaccinated under-50s is small, a report filling out details on each would be illuminating. It would help to address what is otherwise a worrying sign that the vaccines may be counterproductive for younger people.
