4 ms·

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

• maxerickson 6y ago
  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).
  • tertius 6y ago
    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.