U.S. Navy test shows 60 percent of carrier crew have coronavirus antibodies

Re:U.S. Navy test shows 60 percent of carrier crew have coro... by baxtr on Monday June 08, 2020 @04:44PM (#23460560)

I know a person who had mild symptoms, was tested positive in the PCR test and did not have any antibodies 6-8 weeks later. He then looked into the subject deeply. His conclusion was: You can develop antibodies after infections, but not everybody does. Also: a lack of ABs does not mean that you aren't immune. After all, many people were asymptomatic or showed only mild symptoms without any ABs... There is the second, much less known immune system called cellular response, which seems to play a strong role in this disease.

[ Parent | on HN ]

Re:U.S. Navy test shows 60 percent of carrier crew have coro... by KCUOJJQJ on Monday June 08, 2020 @04:59PM (#23460743)

Isn't it also possible that the PCR test was wrong and it was something else, like a cold?

[ Parent | on HN ]

Re:U.S. Navy test shows 60 percent of carrier crew have coro... by rockinghigh on Monday June 08, 2020 @05:39PM (#23461098)

The PCR test is a very specific test. A positive test means the RNA sequence of SARS-CoV-2 was detected. A negative test, however, would not be as strong of an indicator as false positive rates are quite high early or late in the infection (https://www.biotechniques.com/coronavirus-news/news_false-ne...).

[ Parent | on HN ]

Re:U.S. Navy test shows 60 percent of carrier crew have coro... by baxtr on Monday June 08, 2020 @05:10PM (#23460854)

As far as I know a false positive in PCR is not very likely, but of course it is possible.

[ Parent | on HN ]

Re:U.S. Navy test shows 60 percent of carrier crew have coro... by T-hawk on Monday June 08, 2020 @05:50PM (#23461206)

PCR is very unlikely to give a false positive if you never had the virus. The viral RNA simply isn't present to be detected. A false positive from PCR most likely came from contamination of the test materials.

PCR is quite likely to give a false positive if you previously had the virus but have recovered, including asymptomatic cases. There are still pieces of viral RNA that can be detected by PCR, even if they're inactivated by having destroyed the viral coating and you're no longer contagious.

So PCR is pretty accurate at saying if you ever had the virus, but not so accurate at saying if you currently have it at contagious levels.

[ Parent | on HN ]

Re:U.S. Navy test shows 60 percent of carrier crew have coro... by rb808 on Monday June 08, 2020 @06:13PM (#23461396)

Or the antibody test was wrong. Seems most of the tests look super noisy.

[ Parent | on HN ]

Re:U.S. Navy test shows 60 percent of carrier crew have coro... by pengaru on Monday June 08, 2020 @04:53PM (#23460661)

I'm under the impression that not much confidence can be placed in the results of a single AB test.

[ Parent | on HN ]