It’s an old point, but as vaccine mandates are proposed across the world, it bears repeating: It is highly doubtful that the vaccines do anything to reduce transmission at all.

In all likelihood, they merely reduce your chances of testing positive for several months, because they moderate the symptoms of infection and because governments subject the unvaccinated to closer diagnostic scrutiny.

Graphs like this one, from the Swedish matched cohort study, merely compare rates of confirmed symptomatic infection.

They don’t confirm that SARS-2 is actually less prevalent among the vaccinated or suppressed in highly vaccinated populations.

The more you control for different rates of testing, the harder it gets to find vaccine effectiveness against transmission, and the more you start stumbling over evidence of negative efficacy. This is why we find evidence of negative efficacy in the UK data but not (for example) in the German data. In the UK, unlike in Germany, the unvaccinated are not subject to constant testing rules. In Israel, all national airport arrivals are tested regardless of vaccination status. These numbers, widely discussed a few weeks ago, show far lower third-dose efficacy than claimed, and also indicate negative efficacy among the double vaccinated for the month of August. Because unvaccinated arrivals to Israel are quarantined and subject to additional testing, however, even these numbers are imperfect.

When you test everyone all the time regardless of vaccination status, a very different picture emerges.