[mmmrtl]

stopping transmission is an impossibly high bar. Vaccines reduce transmission. Really really shockingly unexpectedly well for the first few months, in previous waves, but that sterilizing antibody-mediated immunity wanes. The booster restores that efficacy against transmission, but omicron's immune evasion means that even a booster only gets to ~70% efficacy against cases/transmission, compared to the surprise finding of ~95% efficacy for the first two doses. Fewer people spreading the virus -> fewer cases -> not as bad of a time.

The other important factor is that because your immune system is primed to recognize SARS-CoV-2 after vaccination, even if you do get infected, it responds and clears the infection more quickly than it would otherwise. That could mean you're never infectious, or infectious for fewer days, reducing transmission. Pre-omicron, breakthrough infections were infectious for 5.5 days on average, compared to 7.5 days for infections in unvaccinated people (https://www.nejm.org/doi/full/10.1056/NEJMc2102507). Yes, all this to maintain some semblance of healthcare for society, and to fill up fewer reefer trucks with body bags.

[Jimmc414]

I don't believe that is accurate. Several studies show no significant difference between the viral load of vaccinated and unvaccinated. Here is one https://www.ucdavis.edu/health/covid-19/news/viral-loads-sim...

Also, recent reports from Denmark seem to indicate that vaccinated at best have equal protection against Omicron. Too early to declare this as fact, but the initial data actually favors a slight negative efficacy.

[mmmrtl]

Confirmation bias is a tricky beast...

Even if Ct values are unchanged between vaccinated and unvaccinated cases, this is conditioned on being infected in the first place, and isn't the whole story. Duration of infectiousness matters.

Yes, boosters are necessary to reduce infection with Omicron, the antibodies from the original vaccine are just too big of a mismatch. That's not news. I'm glad to hear you're not taking those negative efficacy estimates at face value - it's almost certainly the result of missing confounders present at the start of their omicron wave. Unvaccinated individuals are probably less likely to live in urban areas, travel internationally, or even seek a covid test, for example.

[nojokes]

Ct value is just a proxy to viral load and it has been found that the same Ct value results in less cultivable virus for vaccinated.

This negative effect is really most likely because of some confounding factors as others have said. I have seen claimed ADE as always but for that to be true I would expect recent vaccination to offer less protection not more and boosting offer less protection and not more.

[mmmrtl]

Dropped the citation. https://www.nejm.org/doi/full/10.1056/NEJMc2102507 Thanks to the NBA for good time series data

[landemva]

Polio was stopped. Since we can't stop Covid in wild animals, and since severity is moderating, when do we plan to end Covid mandates?