In order to assess the risk from the breakthrough cases, we'd need to know stuff that the ratio of breakthrough cases to total cases, and the ratio of breakthrough cases to the number of people vaccinated vs. the rate of cases in unvaccinated people. Have medical researchers done anything to assess these risks? I haven't seen these sorts of data anywhere I've looked.
Yes, I've seen it. Mostly from the countries or localities where nearly everyone is vaccinated though, which makes the math easier. I haven't seen the data disentangled in a reasonable way from a poorly-vaccinated country like the US.
Breakthrough cases are getting significant in the nearly-fully-vaccinated countries like Israel. They are still much less likely than cases among the unvaccinated -- some estimates were saying 1/10 as likely, and I believe that.
But unfortunately the new variants are VERY contagious. Delta far more contagious than the Baseline strain, Omicron possibly up to 50 times more contagious than the baseline strain. And the baseline strain was pretty contagious! So even if we forcibly vaccinated everyone, that by itself is just not good enough to prevent transmission. We need at least one extra layer of public health defense to get this shut down, and masks are the best candidate for that layer.
Because if everyone wears masks they seem to also reduce transmission to 1/10 what it would be otherwise, or better, from the South Korean studies. If vaccines reduce transmission by a factor of 10 and masks reduce transmission by a factor of 10 then both together is a factor of 100 -- reducing transmission to 1/100 what it was among the unvaccinated-unmasked population -- and now we're actually getting somewhere.
(Also, Omicron is vaccine-resistant, though it's not clear exactly how much. So far it looks like, against Omicron, everyone wearing masks but not being vaccinated would be somewhat *more* effective than everyone being vaccinated but not wearing masks. Of course both vaccinated and masked is better.)
Also, I'd like to see if someone has any quantitative information about the prevalence of asymptomatic carriers, which I think would be one of the most important things to know if we're going to get a handle on controlling the pandemic.
This has been quite hard to measure because most countries don't have surveillance testing. A few results from universities and other such places which do do surveillance testing was suggesting that at least HALF of all cases were asymptomatic. Possibly more.
Specific case tracing from South Korea IIRC (or maybe it was Singapore? Or Hong Kong? I'm getting a few of the studies mixed up at this time) was showing that asymptomatic carriers were the source of huge superspreader events in multiple cases, so the asymptomatic carriers are actually key to stopping the pandemic.
The asymptomatic carriers need to wear their masks, and any of us could be one of them -- unless you're taking two rapid tests per day you just don't know.