Dodgy data: COVID vaccine benefits exaggerated due to mislabelling jabbed as unjabbed, new study shows

We recently reported on the excellent article by Fung, Jones, and (BMJ editor) Doshi, on biases in observational studies that likely exaggerate the effectiveness of the COVID-19 vaccines, particular the case-counting window bias, whereby COVID cases in the jabbed, but before the 1-3 week window to reach ‘fully vaccinated’ status is over, are ignored, allowing a vaccine with effectiveness of 0% to be perceived as having effectiveness of 48%. Now, a follow-up article reveals several ways in which the situation may be worse.

Also published in the prestigious Journal of Evaluation in Clinical Practice, and available open access to all (no paywall) thanks to the wonderful University of Sydney, the brilliant and incredibly attractive author reveals:

• The ‘case-counting window bias’ is often accompanied by a ‘definitional bias’, whereby the COVID cases in the vaccinated are not just ignored, but shifted over to the unvaccinated. So building on the example in Fung et al., “a vaccine with 0% effectiveness” can actually be “perceived as having 65% effectiveness”.

• The peer-reviewed article also shows, touching on the always intriguing (horrifying?) issue of negative effectiveness, “a vaccine with −100% effectiveness, meaning that it makes symptomatic COVID-19 infection twice as likely, can be perceived as being 47% effective”. Furthermore, “Repeated calculations will show that moderate vaccine effectiveness is still perceived even with actual vaccine effectiveness figures of −1000% and lower.”

• The author, Lataster, also explains that this can also happen in studies on vaccine safety, which would be important when comparing the overall health of the vaccinated and unvaccinated, as may be appropriate when looking into “the mysterious rise in non-COVID excess deaths post-pandemic”. Source.

So, the clinical trials for the ‘safe and effective’ mRNA vaccines were very unimpressive, and now it looks like the vast majority of the observational studies concerning the jabs can be thrown out, too.

Okay then.

Extra: The publisher accidentally mixed up the order of some of the content; the sentence before Table 1 should appear after Table 1, and all of that should appear around the end of the section. The comments above, however, should hopefully make clear what it all means. And yes, the author is me. This is my first academic article on COVID, with more planned. The fight goes on.