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Comment by claudeganon | Hacker News Reader

Even achieving something comparable to prior year’s flu vaccination would not bring us anywhere close to the herd immunity threshold though. I’m not as concerned with production of the vaccine itself as the logistics involved. I find it hard to believe that a country that otherwise can’t deliver the basic protective necessities to frontline workers is suddenly going to pull out a logistical miracle out of their hats.

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Something like 5 or 10 million people are acquiring natural immunity each week right now (it's maybe not that high, but there are 1 million+ positive tests each week, with quite high positivity rates, which indicates testing isn't sufficient to find all cases). It's a grim statistic, but the raging spread of the virus is accelerating the timetable for reaching herd immunity.

140 million vaccinated (approx the number of flu vaccinations administered last year) + tens of millions with natural immunity does put us close to the herd immunity threshold (the number of people that have immunity from an infection has big error bars of course, and there will likely be overlap)

Test positivity does not map one to one with people. If someone takes two tests, you get two positives.

Also, acquired immunity might not be forever. Could be possible to get reinfected.

And you have a very optimistic understanding of how many vaccines can be manufactured and distributed, I would guess.

The 14.5 million are cases that have been identified with a positive test. There are certainly more people that have been infected than that, the only question is how many.

Distributed, probably so. I don't see any reason to doubt the manufacturers statements yet, and I'm not including the potential/likely J&J vaccine.

And while we don't know how long acquired immunity lasts, it's pretty clear that it lasts a good while (it's still a freak occurrence when someone tests positive after recovering from a first infection).

It seems right now we're at 10-15% positivity on PCR. And I think that probably maps onto society... So there's a vague guess how many will test positive with PCR.

Unfortunately a PCR result at a 35 cycle threshold (which the vast majority of tests in the U.S. are) does not prove that a person was infected and has immunity, only that there was exposure that is detectable. It may never even have entered the bloodstream.

Only antibody testing will show if there was a immune response and if there is immune memory. We're not doing that at scale.

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