Because of the temporal healthy vaccinee effect, there is a very low number of deaths in the first few weeks after vaccination in the ONS dataset and in other datasets: https://sars2.net/connecticut.html#Comparison_of_deaths_by_weeks_since_vaccination_to_other_datasets. In February 2021 a large part of all vaccinated people had still been vaccinated recently, so vaccinated people had very low non-COVID mortality. And a corollary of the temporal HVE is also that there was temporarily elevated non-COVID mortality among people who remained unvaccinated when the first dose was rolled out.
There was also high COVID mortality in February 2021 which further increased the ratio between unvaccinated and vaccinated ASMR. In February 2021 COVID ASMR accounted for about 41% of total ASMR in unvaccinated people but only about 20% of total ASMR in vaccinated people:
month Unvaccinated Vaccinated # COVID ASMR as percentage of total ASMR
2021-01 47 54
2021-02 41 20
2021-03 18 6
2021-04 6 2
2021-05 3 1
2021-06 3 1
2021-07 14 3
2021-08 24 5
2021-09 22 7
2021-10 20 6
2021-11 25 6
2021-12 28 5
2022-01 32 10
2022-02 19 7
2022-03 15 7
2022-04 17 10
2022-05 9 4
I believe there are two main reasons why the ratio between unvaccinated and vaccinated ASMR was not as high in January 2021 as in February 2021. One is that vulnerable groups of people had been priorized for early vaccination. And the other is that vaccinated people had high COVID ASMR in January 2021 because there had not yet been enough time for the immune response to build up after vaccination, and because many vaccinated people had not yet gotten a second dose.
Just to note, there is one outlier: Febr.21 ratio 5,8. Is there any explanation for this?
Because of the temporal healthy vaccinee effect, there is a very low number of deaths in the first few weeks after vaccination in the ONS dataset and in other datasets: https://sars2.net/connecticut.html#Comparison_of_deaths_by_weeks_since_vaccination_to_other_datasets. In February 2021 a large part of all vaccinated people had still been vaccinated recently, so vaccinated people had very low non-COVID mortality. And a corollary of the temporal HVE is also that there was temporarily elevated non-COVID mortality among people who remained unvaccinated when the first dose was rolled out.
There was also high COVID mortality in February 2021 which further increased the ratio between unvaccinated and vaccinated ASMR. In February 2021 COVID ASMR accounted for about 41% of total ASMR in unvaccinated people but only about 20% of total ASMR in vaccinated people:
> ons=fread("https://sars2.net/f/ons.csv")[ed==7&age=="Total"]
> o=ons[status%like%"accin",asmr[cause=="Deaths involving COVID-19"]/asmr[cause=="All causes"]*100,.(month,status)]
> o[status=="Ever vaccinated",status:="Vaccinated"]
> round(xtabs(V1~month+status,o))
month Unvaccinated Vaccinated # COVID ASMR as percentage of total ASMR
2021-01 47 54
2021-02 41 20
2021-03 18 6
2021-04 6 2
2021-05 3 1
2021-06 3 1
2021-07 14 3
2021-08 24 5
2021-09 22 7
2021-10 20 6
2021-11 25 6
2021-12 28 5
2022-01 32 10
2022-02 19 7
2022-03 15 7
2022-04 17 10
2022-05 9 4
I believe there are two main reasons why the ratio between unvaccinated and vaccinated ASMR was not as high in January 2021 as in February 2021. One is that vulnerable groups of people had been priorized for early vaccination. And the other is that vaccinated people had high COVID ASMR in January 2021 because there had not yet been enough time for the immune response to build up after vaccination, and because many vaccinated people had not yet gotten a second dose.