Respiratory virus vaccines are just not terribly effective over a long period of time, as we saw with the CV-19 vax. Influenza vaccines have shown a similar limited effectiveness. A new paper suggests, quite wrongly, that receipt of the vaccine might actually be associated with a higher likelihood of getting influenza. The study was conducted at the Cleveland Clinic over the 2024-25 flu season. The study population was persons who were employed at the Cleveland Clinic as of October 1, 2024, so not a representative population at all. Not a great setting for such a study either, as a health care facility both has greater likely risk of flu being present but also workers taking greater precautions. The comparative incidence of flu among those vaxed and unvaxed in the population over the next 25 weeks was the primary outcome.
82% of the employees got the vax, which was a little odd because the Cleveland Clinic made it mandatory so how did such a high percentage get away with not being vaxed. And about 2% got the flu during the study period. Supposedly a higher proportion of the vaxed than unvaxed contracted influenza. But here is the problem–a confirmed flu diagnosis requires a test. Now do you think that the people who dutifully took the flu shot and the people who found some reason to avoid it are equally likely to get themselves tested for flu if they have symptoms? Of course not. The dutiful group is almost certainly much more likely to get tested and those who didn’t get vaxed are also more likely to blow off their symptoms as just a cold. And the unvaxed group may have just in general perceived themselves to be healthier so less in need of a vax or testing for symptoms. The authors don’t present enough data to really understand who did and didn’t get tested. The study should have included mandatory regular testing of all employees in the population. But it gave enough data to tell that the vaxed did get tested more frequently. And please note the extremely wide confidence interval (the range around which it is 95% certain that the results reflect reality) which is a strong indicator that the supposed effect is in fact very weak. (Medrxiv Paper)
William Briggs, a statistician who is worth following both for education and for his informed take on many research issues, wrote an excellent critique of the flaws of the study, far better than I could do. His basic point is also that the study inadequately addressed confounding around who got the vaccine and who was more likely to be tested for flu. And in fact the data show that the vaxed were more likely to get tested. Look at the charts in the paper, which Briggs reprints and pay close attention to his point about how visually misleading some presentations of data are. The dots are all over the place but by God, if you want to you can make a “best fit” line that supposedly tells you something. It also appears that men were much less likely to have the flu but this too is almost certainly due to men generally being less likely to get tested–many of us are still pretty macho. Failing to do that makes the results worthless. As noted at the top, the flu vax does not have high efficacy, but I seriously doubt the results of this study. (WB Substack)
Excellent comment on the statistician. Far too many studies lack adequate cross checks of their math. Basic principles of math learned in high school with algebra or proofs from geometry are ignored. These common errors were most evident with covid studies, along with much of the climate studies, especially the paleo research.
I know of quite a few people that do not get the flu vaccine. Instead they are rigorous in getting tested when they do get sick, because then they can get the medicines that treat it and are over it quickly. Conversely, I know people that get the vaccine and then assume what they have is not the flu, because they have the vaccine. That is the opposite of your supposition above… Wether that holds true for a larger population, or one in a Clinic – I don’t know.
My have nothing to back it up other than my own general observations of what I see and who I run into on a daily basis, but I’m skeptical that both the flu and COVID vaccines do any good at all or cause any harm at all. I’m open minded to both arguments, but I have yet to see anything with my own eyes to believe either side. My suspicion is that they’re there to increase the revenue to the pharmaceutical companies (insurance pays so you may as well get it) and health insurance industry (increased “free” vaccines justify increased rates) and not much else. The part that bothers me is they’ve convinced the medical establishment that it’s absolutely necessary and you’re a kook if you have any questions about it.
At the same time, I’m also very skeptical that they are harmful. I just think they don’t really do anything at all.
The issues with this study certainly obviate its usefulness for detecting a small effect. But that raises a different question: Shouldn’t the flu vaccine produce more than a small effect? The claim of those vaxed being more likely to get the flu seems to be unfounded. But the real result might be that any benefit of the vaccine may have been small enough to get lost in the statistical issues.
Flu shots/jabs (not to be confused with vaccines that by historical definition meant permanent immunity, (e.g., smallpox, polio) used to be just for the specific strain of flu expected for that season, if I recall correctly. So, one could get a shot for influenza A but still come down with influenza B, for example. And, I believe it was quite common that the “expected” strain for the season was often not the most prevalent strain, thus making the shot for that season essentially worthless. So, if it remains the case that the shots are given for a specific strain, I didn’t see in my cursory skim of the study that it addressed that, not that I’m defending the study at all and no disagreement with your assessment.