Some of our best evidence so far comes from this Swedish retrospective cohort study, which tracks outcomes in 1,684,958 individuals (matched vaccinated and unvaccinated pairs) from 12 January to 4 October 2021. It has been around the block, with an especially good analysis by El Gato Malo, so there’s no point in anything more than a brief review here. Above all, they find that the vaccines provide temporary protection against infection:
Unfortunately, this protection likely falls below zero – into the zone of negative efficacy – after 7 to 9 months. This is one of multiple lines of evidence confirming that the vaccinated, sooner or later, achieve higher rates of infection than the unvaccinated. According to me, even early vaccine efficacy is likely overstated in studies like these. Probably the vaccinated are always highly vulnerable to infection, but they’re not tested as rigorously and at first their symptoms are so mild as to be nearly unnoticeable. SARS-2 nevertheless lurks among them, mostly undetected, until vaccine protection against overt disease dissipates.
So those are the benefits, but as in everything there are also costs – and here they turn out to be substantial.
We’ve already touched on one: The vaccines appear to induce negative efficacy against infection. This probably arises from a combination of minimally symptomatic super-spreading among the vaccinated, the selective pressure that vaccine-elicited antibodies place upon the virus, and the narrow immunity against an obsolete arrangement of the spike protein that the vaccines confer. For a period of several weeks after dose 1 (and likely dose 3), they also make the vaccinated more susceptible to infection, and mass vaccination campaigns have induced case spikes across many countries.
By now it is also clear that the vaccines cause a range of adverse reactions. The best documented is myocarditis in young men, a side effect observed most frequently after dose 2 of the mRNA vaccines. We probably won’t know the true rate of vaccine-induced myocarditis for many years. From excess mortality in younger cohorts and many anecdotal media reports, we can surmise that it is much more common than anybody will admit.