I was reviewing the Technical Briefings and something struck me odd when I compared it to the Vaccine Surveillance Reports.

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1001358/Variants_of_Concern_VOC_Technical_Briefing_18.pdf
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1039677/Vaccine_surveillance_report_-_week_49.pdf

When I calculated the case fatality rate (measured by death / positive test), I got the following results:

Unvaccinated INCREASED from 0.1278 to 0.1841
[despite the massive vaccination from older people which should have the reverse effect as only younger people are left and thus less susceptible to COVID-19]

Vaccinated ONLY DECREASED from 1.0891% to 0.5269%
[despite the massive gain in younger people which should be decreasing much faster because now it engulfs a large portion of younger people]

Now you could argue that is simply because the reports use a case positive test and these deaths could be related to other causes. But when you got to the Office National of Statistics..

https://www.ons.gov.uk/filter-outputs/7316c919-d4e8-406c-af7d-6c7aca1eedf4

Every age group from week 27 up to week 49 that I monitored has had excess mortality. What's worse is that every age group has also had more deaths from COVID-19 than the previous year (which is more or less the excess mortality calculated with the exception of two age groups but that's not important for what we are discussing). Only those aged 75+
aren't dying in greater numbers from COVID-19 than the last year (understandably so since they were the most at risk).

Maybe I'm missing something but shouldn't this mean that Delta became stronger over time? I cannot see a reasonable explanation for this as hospitals aren't t over capacity like last year.