Coronavirus (COVID-19) Discussion Thread

[haxxiy]

Lafiel said:

haxxiy said:

Antibodies target a single antigen, and these tests are done with Covid-19 antigens to see if there's an immune response. While it's technically right to assume closely related viruses could elicit the same immune response due to cross-reactive immunity, it does also mean that whatever is in these people's blood has specifically reacted to Covid-19 antigens and would (very likely) neutralize the virus.

From what I read a lot of antibodies unfortunately have little effect on virus activity, if they bind too losely/don't bind to the specific antigen (hull structure) that is related to a viruses reproduction. Scientists think for SARS-CoV-2 the antigen that allows it to use the ACE2 receptor to invade cells is the crucial one, so it's possible only antibodies for this one grant a strong immunity.

Every virus has a multitude of different hull structures, so it's possible the study in question used an antigen which is not uncommon in the other corona viruses.

You are not wrong, but antigens are also incredibly specific. Small genetic variations drastically change how proteins fold on themselves, and loose bindings won't make through the end of the test, as there are 'sievings' to do away with these. Unless there's strong evidence to systematic errors in the samples, substrate, enzymes etc. that were used, I'm going to assume the standards of good scientific practice were followed.