What is the point of antibody testing?

[Miljea]

what IS the point of anti-body testing?

BBC site.

We (NHS) in a now low-risk area are offered this. Several of my colleagues go weekly to get their always negative test, but seeing as we don't do anything with the information, and you might be negative today, but positive tomorrow, and given how much immunity having had Covid confers upon the individual (if any at all), it does seem an expensive pointless undertaking.

And, of course, some insurers are refusing insurance to individuals who have tested positive!

[ThatDamnScientist]

Forgive my ignorance but I don't get the point of weekly antibody tests. If it was negative the previous week then you would surely need to leave a reasonable time between tests as you would then need to contract covid to produce antibodies so would need to allow time for the disease to run it's course through your body? I can understand weekly antigen tests to see if you are actually asymptomatic positive.

[Gluestick80]

They surely don’t have an antibody test weekly. Do you mean they have a weekly swab? Most of the staff at my hospital have a weekly swab but not a weekly blood test for antibodies.

[sashagabadon]

@Miljea

what IS the point of anti-body testing?

BBC site.

We (NHS) in a now low-risk area are offered this. Several of my colleagues go weekly to get their always negative test, but seeing as we don't do anything with the information, and you might be negative today, but positive tomorrow, and given how much immunity having had Covid confers upon the individual (if any at all), it does seem an expensive pointless undertaking.

And, of course, some insurers are refusing insurance to individuals who have tested positive!

it;s not weekly antibody testing - it's weekly covid swabbing so they know as much as poss their staff do not have covid at that moment in time.

you have misunderstood

we are all getting tested for antibodies at moment however, but just once

[Miljea]

Nope, assuming the antigen test is a needle in the arm, which is what they're lining up for- they're going weekly.

You only get swabbed if you're symptomatic or in contact with a positive, without PPE.

But, regarding the two week antibody thing, surely if you test weekly, it's looking for the CV you recovered from (symptomatically) 2 weeks before? Which makes sense given that we all are exposed to it every working day? So last week's test might come back negative as I'm only a week past having it, but next week's will be positive?

[ThatDamnScientist]

The swab to test for active cases is an antigen test. Antigen tests are only for live cases and doesn't look for antibodies. I will be honest, I am struggling to understand why they would be taking blood samples to mass test for positive covid cases - point of antigen testing is it is quick turnaround - processing blood samples would be time consuming ( happy to be corrected by more knowledgeable people on that score).

If they are all being tested for antibodies weekly then that is in my opinion is an issue - symptomatic and asymptomatic cases don't always produce antibodies, the disease could be handled by TCells meaning no antibody response is triggered (this is more likely in asymptomatic cases I believe, though both can go either way). The other thing is, even if you have antibodies it doesn't imply long term immunity - two papers (at least one not yet per reviewed) have claimed after two months antibodies are declining rapidly. So again, if they are doing repetitive/ weekly antibody tests on the same people rather than doing one blanket check of everyone to see if they have antibodies and then continuing with weekly antigen tests to monitor live cases in nhs settings I don't understand the logic.

[Miljea]

Sorry, I meant antibody test! That's the blood test, isn't it?