> Vaccines have been trialled using not symptomatic illness, but actually PCR tests for immunity, and found over 90% immunity with symptoms||viralRNA as a standard. So no, it's actually around 10-20x less likely to have infection, too. For things like severe ilness, it's more like 99-100%.

The only vaccine I'm aware of that had weekly PCR surveillance was the Oxford/AstraZeneca vaccine, which showed an efficacy of 57% against a positive swab (95% CI -- 41% to 66%; 95% CI efficacy against asymptomatic illness -17.2% to 54.9%). If you know another one that showed 90%+, please cite! Both the Moderna and Pfizer trials relied upon symptomatic illness (symptoms + PCR confirmation) as an outcome measure.

> During this window if the individual is vaccinated before antibodies show up there is very little pressure to evolve resistance against them.

No, but you can get a infection that shows up as antibody response is ramping. Neither infection and vaccine response are nice clean instantaneous, atomic events.

> Given the fact that we have seen zero severe illness in even very old people with many vaccines

You have to consider the statistical power of the study. In the very old people (75+), you're talking about 0 vs. 5 cases (symptomatic) in the Moderna study, for instance, with unknown impact on any symptomatic infections. You seem to be concluding an awful lot based on 0 vs 5 symptomatic cases in a short study period for what the outcome will be across a population of 18 million people in the US.

> If the same individual was vaccinated, this would have been impossible

Why? We've seen it happen in the wild with COVID (long illness times and failed immune clearance), and we've seen it with existing vaccines in other illnesses. "Impossible" is a very stronk word.

> Even for those, the vaccine is still incredibly efficacious. The differences IIRC are barely statistically significant. If you have a source for more significant variations I'd love to see it.

We don't know the efficacy for subvariants. We have nowhere near enough n. We do know that even during the phase 2 trial, there are serum neutralization titers for variants that the error bars do not overlap for, and the MLEs are an order of magnitude apart.

> It's possible that this happens, eventually - think years. Not in the 1-3 months period we're talking about.

First, it's more like a 6 month period, and longer when we consider the entire world.

> The result is that it doesn't make sense to vaccinate 20-40 year olds in priority or to sell the vaccine on the free market, at all.

Which, I understand, are things the original article advocated for, but I never did-- indeed I mocked it in other comments e.g. here https://news.ycombinator.com/item?id=25609607 https://news.ycombinator.com/item?id=25609600 and in a comment on the original article. So really, come on. Argue with what I'm saying, not the make-believe argument you'd like to have.

The epidemiological and immunological communities consider it a risk, and I've shared papers. Here's what widely-followed Derek Lowe has to say:

"The good news continues to be that none of the mutations studied so far in the general population seem to be able to evade the antibodies raised by the current vaccines. That doesn’t mean that it can’t happen – and as we start putting selection pressure on the virus by vaccinating people we’ll have to keep a close eye out for anything like that developing. But then we have to consider transmission. If an antibody-evading form of the virus also becomes harder to catch, well, it’s going to be less of a worry. But if we were to start doing a better job at not spreading the virus in general, that would be sort of nice, because that would reduce the chance that any nasty mutated forms get any kind of traction in general. If some sort of supervirus mutation occurs in a single patient who doesn’t then get close enough to other people for it to spread, then it’s a tree falling in a forest that doesn’t make much of a sound."

"It’s all a race between several different factors. But here in the US we have so many people infected (and so much transmission going on) that frankly we’re making ourselves vulnerable to any more dangerous mutations that might crop up. In fact, if something like that were to emerge, the odds are better that it would do so here, from what I can see. We’re giving the virus every opportunity to reproduce and for the subsequent viral variations to then go out and try their luck infecting lots of other people. Vaccinating enough people quickly enough would interrupt these processes, and so would doing the sorts of public health measures that we’ve all been hearing about for months. But the first is going to depend on vaccine supplies, logistics, and public acceptance, and the second, well, look around you, si monumentum requiris."

https://blogs.sciencemag.org/pipeline/archives/2020/12/10/th...

Which is broadly in agreement with what I'm saying.