One of the strangest things about the last few months on planet Earth has been the relentless drive to vaccinate everyone, regardless of what their individual risk from the virus is, and whether or not they’ve already had the disease. It was well known long before covid came along that people who have had an infection are usually at least as well protected as those who get vaccinated. The whole point of vaccination is, after all, to mimic infection so as to stimulate immunity. If you’ve had measles, you don’t need to take the measles vaccine. If you’ve had hepatitis A, you don’t need to take the hepatitis A vaccine. If you’ve had chickenpox, you don’t need to take the chickenpox vaccine. Yet if you’ve had covid, you should supposedly still take the covid vaccine. Strange.
The obsession with vaccinating everyone is particularly odd in a situation where access to vaccines is limited and the stated goal is to reach herd immunity as quickly as possible, since wasting time vaccinating people who have already had the infection will inevitably delay the time it takes for a population to reach herd immunity.
Yet many people who should know better have been happy to play along with the “everyone needs to be vaccinated” mantra, in spite of the fact that it runs counter to the stated goal of governments and public health agencies. Many doctors had covid during 2020, yet they were more than happy to stand at the front of the line and take the vaccine in late 2020 and early 2021, even though they knew (or should have known) that they were almost certainly already maximally protected from the virus, and that taking the vaccine would inevitably mean a delay in vaccination of those who had not yet had the infection.
A few months back I wrote about a study, published in The Lancet in April, that showed a 93% decreased risk of re-infection in people who had already had covid. That would make prior infection equivalent to the most effective vaccines, in terms of its ability to protect against covid (which is as we would expect).
For those who remain unconvinced that prior infection is at least equivalent to vaccination, however, a very interesting study was recently posted on MedRxiv. This was a retrospective cohort study of the 52,238 employees of the Cleveland Clinic, who were followed from December 16th 2020 (when the Cleveland Clinic started vaccinating its staff) until May 15th 2021. The objective of the study was to compare the relative rates of infection between four groups of employees: Thos who had had covid and been vaccinated, those who had had covid but not yet been vaccinated, those who had not had covid but had been vaccinated, and those who had neither had covid nor been vaccinated.
A PCR test was used to diagnose covid in the study. The Cleveland Clinic was not engaging in any screening of asymptomatic staff during the study period, so tests were in almost all cases carried out when participants developed symptoms suggestive of covid. In other words, the method used to diagnose covid in this study was equivalent to the method used in most other studies, and also the method that is used in the real world.
So, what were the results?
There were 2,139 new covid infections among the 52,238 participants. In other words, 4.1% of the participants in the study developed covid during the five month period. 99.3% of these infections were among participants who had neither had covid nor been vaccinated. The remaining 0,7% were among participants who hadn’t had covid but had been vaccinated.
2,579 participants had already had covid at the start of the study. Not a single one of them developed covid during the five month period. This includes both the 1,229 with prior infection who were vaccinated, and the 1,359 who weren’t. What that means is that prior infection was associated with a 100% reduction in the relative risk of infection. That was true regardless of whether the person with prior infection was vaccinated or not. Vaccination did not provide any additional benefit to those who had already had covid.
What can we conclude?
Prior infection is highly effective at protecting against covid. There is thus no need for people who have already had covid to get vaccinated. When governments do vaccinate people who have already had covid, they are wasting taxpayers money and putting people at risk of side effects for no good reason.