The existing covid vaccines don't really reduce infections. Vaccinated chances of getting infected is about 1/3rd that of unvaccinated if one looks at the official numbers of infections at those places where such numbers are available. Giving that vaccine decreases the symptoms it is natural to expect that all those hordes of asymptomatic vaccinated virus spreaders aren't accounted for (CDC wouldn't count breakthrough until it is a hospitalization). The precise estimates of those unaccounted breakthrough is a wild guess, yet ballpark estimation (based on asymptomatic to symptomatic ratio for vaccinated which is much higher that that ratio for unvaccinated) brings vaccinated infection rate on par to that of unvaccinated.
Do you really need to wild guess? Couldn't you randomly test both vaccinated and unvaccinated people and see which group gets infected more often?
https://www.science.org/content/article/grim-warning-israel-...
" Israel has among the world’s highest levels of vaccination for COVID-19, with 78% of those 12 and older fully vaccinated, the vast majority with the Pfizer vaccine. Yet the country is now logging one of the world’s highest infection rates, with nearly 650 new cases daily per million people. More than half are in fully vaccinated people"
more-than-half. Say 55%. 22% gets 45%, 78% gets 55%. I.e. the 1/3rd as i said.
The vaccine loosing effectiveness and the occurrence of partially vaccine-evading variants have been predicted from the outset. The open question was always where and when that would happen.
Edit: references for the Israeli case load and development over time https://graphics.reuters.com/world-coronavirus-tracker-and-m... You can clearly identify the two peaks, about 6 month apart.
>The vaccine loosing effectiveness
it never been effective at controlling the spread. It was developed for Alpha and was obsoleted almost immediately by Delta.
That's measure people who got the vaccine and then got infected. It's not factoring in how the vaccine reduces infections.