- Re: No Archived Message
Posted by Shyaku
on April 3, 2020, 7:35 pm, in reply to "Re: No"
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I didn't say it was of no use, these are your words. I wrote that it tests for prior exposure The test for exposure will aim for epitopes that give good sensitivity, which are not necessarily ones that neutralize virus. Your question about general usefulness: If you test negative in the antibody test, you are not immune because there has been no exposure according to the most sensitive indicator. If you test positive you might be immune with some rather undefined probability. The reason it is undefined is because, basically, the only real test for immunity is a challenge experiment: You give the vaccine, then you attempt to give the disease to a set of individuals and score the level and frequency of sickness against a control, unvaccinated group. People (other than maybe the CIA and Japanese military iin WW2) only generally do this experiment in mice. It doesn't work great in mice because their immune systems are sufficiently different from human, unfortunately. This is one excellent reason why vaccines are difficult to develop. When you do field trials with humans you wait for them to infect themselves over some period of time then come back like a year later (which is a bit more ethical perhaps). This is one excellent reason vaccines can be slow to develop. If you ARE immune to COVID, this essentially means you can catch the virus then it becomes suppressed before disease symptoms appear (e.g disease of the lower respiratory tract). However, before it becomes fully suppressed (before immune cells proliferate to high numbers) there is some reasonable possibility you can transmit the virus, for example from the throat area where all COVID infections are thought to initially proliferate. |