Thread by @BillHanage

Vaccines that protect against severe illness and death have been available for more than a year. In this we estimate conservatively that in the US ~135,000 lost their lives to covid over the Delta wave for lack of vaccination medrxiv.org/content/10.110… 1/n

Because vaccines were not immediately available to all we only look at 5/30/21 to 12/4/21, after which omicron rapidly took over and the situation changed (again). By the start of that time even I (youngish, not in a priority group) was vaccinated 2/n

https://twitter.com/BillHanage/status/1389255013332103174?s=20&t=__Ci6C6CuIvkNzkVR07k2A

All this makes use of data from covid.cdc.gov/covid-data-tra… vaccine-status. Please read the preprint for full details, but a few major points follow 3/n

First the vaccination rate did increase among the 18s and over during this period, though not by a lot 4/n

This however, shows the difference in the deaths over this period between those vaccinated and unvaccinated. If you think that is grim, I agree with you 5/n

We then multiplied the mortality rate difference to the total number of unvaccinated individuals in the 26 jurisdictions by age group and week, to estimate the number of excess deaths 6/n

Note this accounts for age, and for the proportion of each age group vaccinated by week. The data are from only 26 US jurisdictions in which we estimated a total of 83,400 excess deaths from lack of vaccination. But we can extrapolate to the rest of the country 7/n

While covid is more serious in older populations, it is not trivial in younger age groups. Estimate 31.1% of these deaths occurred in 50-65 yr olds, 13.9% in the 30-49 age group. You can do the math 8/n

Or alternatively... here's the math done for you 9/n

The full preprint contains various sensitivity analyses on, for instance, the impact of partial vaccination. But the headline conclusion that under vaccination has led to an enormous number of deaths, including in younger age groups, remains 10/n

Notably over this period many parts of the US had already withdrawn mitigations we are now hearing about being relaxed in Europe. Which meant among other things plenty of virus around to prey on the unvaccinated 11/n

and, as I type, 'mild' omicron continues to cause large amounts of death. This should start to decline soon, but the losses will be fewer if we can vaccinate more and boost the vulnerable 12/n

Finally thanks to excellent co authors including the @mlipsitch @DavidSwerdlowMD and Katherine Jia for leading this. As well as the folks at @CDCgov who collect the data and make it available 13/end