This is just a reminder that some of the numbers being bandied about about this pandemic might need a few correction factors. Mostly these make alarmists even more right.
One thing often mentioned is a comparison between total excess deaths and official COVID deaths. The excess death number is about 25-30 (32 percent according to the CDC) percent higher than the official death count in the US and most countries compared to the official count. This makes an argument that the official count is an underestimation rather than an overestimation. But the excess death number is also starting to look like an underestimation. The pandemic has gone on for so long that many of the people who died in 2020 would be dead now. So the background of expected statistical deaths is actually lower than it would have been without the pandemic. Officially 0.7% of people are expected to die each year, which would mean that a background of about 100 people fewer a week would be expected to die 5600 or 7000 per year depending the number you use for the correction. But deaths from COVID in 2020 were concentrated in Nursing Homes. One hundred eighty thousand people died in nursing homes in 2020, and given a life expectancy of 2 years for a nursing home patient half of those would probably be dead by now, which if you were estimating death from the sum of the excess deaths, would lead to an underestimation of 90,000, a big number.
People are always comparing “natural immunity” vs the vaccine. One problem with estimating vaccine efficacy is that the control group is assumed to be unvaccinated with no immunity, but at this point according to the CDC more than 45% (the estimate is for OCT 1) of the population has been infected. So if efficacy is measured by comparing breakthrough cases to a control group of unvaccinated, and half of the unvaccinated are just as immune as the vaccinated, your measured efficacy is going to be low. To make a easy illustration. If a vaccine is 50% effective and the unvaccinated population has had a 50% infection rate with a disease that confers 100% immunity, the vaccine will appear to have no effect. I think in double blind studies this problem is addressed, but in the kind of data put out by health departments that just compare vaccinated and unvaccinated patients it isn’t. Once again, this is probably a large effect, but hard to calculate. The correction suggests that vaccine efficacy is underestimated, but also the disease is more severe and widespread in the unvaccinated and never infected than the statistics indicate. Natural COVID immunity is more complicated, but it is hard to believe there isn’t some effect.
The vaccinated tend to stick together and are probably much more likely to mask and do other things to stay safe. This will also produce a difficult to assess, but non negligible error, in this case it will make the vaccines look better, and even make being unvaccinated seem safer.
So as always, numbers don’t lie, but be careful with them.