To get the death toll from an infectious disease requires knowing two things: lethality and spread. Lethality is measured by the infection fatality rate (IFR), and it indicates the probability of death after you become infected.
Spread is simply the total number of people who have been infected and, because it has the most inherent uncertainty, 5 different levels of spread were used below. One level of spread is the 25% annual attack rate discovered by Ioannidis (cited in the second image below).
The other 4 levels of spread are multiples of the confirmed cases. Research reveals that nations captured from 20% to 50% of the underlying COVID cases. When 50% of all underlying infections are captured, the true number of infections is double the number of confirmed cases.
But if disease surveillance is so poor that only 20% of the underlying infections are getting confirmed as cases, then the true number of infections is 5 times the number of confirmed cases.
It’s easier to discover the lethality of infectious disease than the spread of it. To discover lethality, simply follow tens of thousands of infections through time — and you will have your answer.
Because a hard lower bound exists on IFRs, but no hard upper bound does (you can find death numbers higher than the true IFR, but you cannot find death numbers lower than the true IFR), the best estimates involve the largest cohorts resulting in the lowest IFRs.
From there, you can find a 99% confidence interval around that “large-cohort; low-IFR” data in order to encompass all plausibility. In UK Technical Briefing #5, a large cohort was followed through time, to count up how many died within 28 days of confirmed infection.
They followed 117,000 COVID infections for 28 days and recorded the deaths.
The strains of COVID that they found were wild-type (Wuhan-1) and Alpha variant. Using the estimated lethality from that briefing, along with relative lethality for Delta and Omicron variant, it is possible to perform an impact analysis using multiple levels of spread.
Note how it is that, even with more than 100% spread, at the central estimates of lethality, COVID was unable to explain even a third of the excess deaths in the US for the 24 months from Mar 2020 to Mar 2022:
At bottom, the highest plausible lethality was ascribed to COVID — the 99% upper bound on a confidence interval around the point estimate. Even then, and even with 95% of people being infected by COVID, COVID could not explain even a third of the excess deaths seen in the USA from Mar 2020 to Mar 2022.
Here are the references used in order to come to the conclusion that something else, besides COVID, killed over twice as many people as COVID did: