Re: anthony costello ex director WHO on possible lack of specificity of antibody test. Archived Message Posted by Shyaku on April 5, 2020, 12:05 pm, in reply to "Re: anthony costello ex director WHO on possible lack of specificity of antibody test." Two points: (1) I suspect the false positive rate for PCR is very low. However, so could be the claims of reinfection. So they could match, but nonetheless, there would have to be some reason for a re-test, like a fever and other symptoms, including maybe a CT scan so there are independent indicators. Moreover, there is a possibility of a follow up PCR test with a different set of primers, which would probably be considered worthwhile for someone, unusually, testing positive after recovery. If FPR with primer set 1 = say, 1/1000 and FPR with primer set 2 = 1,000 that is 1/10^6 chance of independent false positives. CDC has three sets of primers. Take home: There should be a way to get to the bottom of false positive vs. reinfection. (2) Neutralizing antibodies are not a perfect correlate to immunity. Yes, if antibodies neutralize virus in a virus neutralization assay they are better than just, more generally, "an antibody reaction" to COVID in "an antibody test" but a virus neutralization assay is too large in scope to be done routinely - it means growing then handling virus in the lab for one thing. But even if antibodies neutralize, there is still not a perfect correlate to immunity because antibodies are just half of the immune system (or less than half). The other half is, in many ways, more important. - Shyaku Message Thread: anthony costello ex director WHO on possible lack of specificity of antibody test. - dan April 4, 2020, 7:03 pm Re: anthony costello ex director WHO on possible lack of specificity of antibody test. - brooks April 4, 2020, 11:51 pm Re: anthony costello ex director WHO on possible lack of specificity of antibody test. - Shyaku April 5, 2020, 12:05 pm Re: anthony costello ex director WHO on possible lack of specificity of antibody test. - brooks April 5, 2020, 1:08 pm Re: anthony costello ex director WHO on possible lack of specificity of antibody test. - Shyaku April 5, 2020, 8:22 pm Re: anthony costello ex director WHO on possible lack of specificity of antibody test. - brooks April 5, 2020, 8:42 pm Re: anthony costello ex director WHO on possible lack of specificity of antibody test. - Shyaku April 7, 2020, 5:27 am better link (i hope) for the Lancet article - brooks April 5, 2020, 1:12 pm   Searching