Should The Government Be Concentrating On Covid Anti-Body Testing?

[AuntPollyGrey]

Would it be more useful to know who had recovered from the virus without any hospitalisation, of even without symptoms rather than who has got it now?.

Someone presenting for a routine test because they are a Key worker could test negative, and then catch it in a couple of days time. What is the point of that?

At least if you know you have had it you may be immune......or is that the problem? The scientists have no idea if you can catch the virus again once you have had it?

[bednobs]

I think the problem is that there is not currently a reliable enough antibody test

[fiction-factory]

The antibody tests will be really useful but they are not available yet for that purpose. I understand no country has a proven one. There is one that is sufficiently reliable to use for data gathering purposes in large sample groups but is not reliable enough to say with any certainty whether someone has actually had Covid

[woofgang]

yes as I understand it the tests are unsafe for use on an individual basis...Prof Whitty called them "useful for a ranging shot" ie they pretty much know the margin of error so can say eg for every 1000 people who look as though they have antibodies, the true figure probably varies between eg 800 and 900...which is useful for modelling and research but unsafe for individuals to rely on.

[AuntPollyGrey]

Ok I'm not a scientist , but how can it be so difficult to identify Covid-19 anti-bodies in a blood sample?

[woofgang]

I am not either (a scientist) but given that so many people are working on it globally and how important it is, I think it must be hard!

[jennyjoan]

NOBODY KNOWS

[mushroom25]

not only are the tests not known to be reliable - but it's also not known what the presence of COVID antibodies actually shows. I mean, nobody seems able to say whether having the disease confers any immunity and/or whether the disease can strike you more than once.

[woofgang]

mushroom, its worse than the tests being not known to be reliable, they are known not to be reliable.

[Zacs-Master]

All a bit pointless if it’s found to be recontractable.
https://edition.cnn.com/2020/04/25/us/who-immunity-antibodies-covid-19/index.html

[MWG14]

Isn’t it amazing just how many armchair coronavirus experts have popped up everywhere!

[Zacs-Master]

Equally as amazing as the amount of people who pop up and say something dumb without contributing.

[woofgang]

MW anybody who bothers to read can quote or repeat information from the people who are the experts or doing their best to become experts. I find it helpful to know what the actual facts are so far as I can.

[Peter Pedant]

// Ok I'm not a scientist , but how can it be so difficult to identify Covid-19 anti-bodies in a blood sample?//
NOBODY KNOWS !

so - - you re a microbiologist ? well that dont impress me much ! thx to Shania Twain

you expected me to rise to that innit ?

long explanation at the end of this thread
https://www.theanswerbank.co.uk/Science/Question1701957.html

to summarise
1. Covid infection raises specific antibodies and this (helps to ) end the infection or else you DDDIIIIEEE!

2.it is possible that some people have antibodies to other things that test positive on the covid test. (false positive ) - but the question is that is the interference common and important ?

3. Gatherer with his own research n Ebola said it was likely

4.The govt which had placed an order for 19m tested 100 systems and found they all failed the quality control which I THINK was 95% chance that if the test was + then the patient HAD actually had the infection.

[theprof]

In an ideal world, you would think that we would all love to know who has recovered from the virus at home or has been asymptomatic either during home confinement or work. Knowing that x number of people at any given time out the population as a whole are free of the pathogen is of limited value to the government or their advisers. Furthermore, such figures could not be taken as accurate. There is also the major risk that any figure could be seriously misinterpreted in some quarters leading to major predicaments for the government and compromising efforts to beat the pathogen. No one knows these figures but I can assure you that will benefit us all in the long term.

Testing is vitally important in order to assess how the pathogen is spreading throughout the community and to put appropriate control methods into place. The fact that someone may test negative on a Monday and positive on a Friday is totally immaterial. Day one begins on the day that key worker becomes positive. You have to remember that trends like this happen with many infectious diseases. It's a continuous process for key workers and will show if a key worker needs to isolate to prevent the transmission of the virus. This process is an important part of keeping the R number below zero and preventing the spread of the disease. This is a key part of saving lives.

The thinking is that exposure to the virus MAY confer some sort of immunity but there is no certainty about it. The press has many anecdotal tales of immunity from the pathogen occurring on the Chinese mainland, but closer examination of the data and their assessment methods have opened up a number of questions that they don't seem to be able to resolve for the rest of the world. There has been little credence attached to the the claims in recent weeks. Besides, at the end of the day, it is vital that the typical duration of any immunity becomes known and that figure remains totally unknown throughout the world right now.

[fiction-factory]

> Thanks theprof
Are you sure you meant "keeping the R number below zero" though?

[douglas9401]

I heard on t'radio earlier that a big problem is the variation in the amount of antibodies in a given testee, thoughts were that the more severe the illness the higher the level but they were still a bit vague overall.

[theprof]

AuntPollyGrey, identifying antibodies can be done readily enough in a laboratory although the quality of the antibodies will remain uncertain. However, there are different types of antibodies and they are not all present at the same time in the host. Their production can vary from hours to weeks. Not all antibodies are able to harm the coronavirus and the some cheap tests for the antibodies are not able to discriminate between the effective antibodies and the less effective types.

The presence of covid19 viral RNA remains the gold standard for the presence of infection but this can only be done in a sophisticated laboratory geared up with the necessary equipment. It cannot be done, for example, in a hospital.

[theprof]

Thank goodness you're on the ball fiction-factory! I intended to put "one" there but I was thinking of how to put a subscript "0" after the "R" and senility took over.

My apologies.

[jim360]

Thanks for the input prof, how is the research going?

[theprof]

douglas9401, you're absolutely right. I touched on the antibody quantity issue in my answer. Antibody quantity is not necessarily linked to severity of infection but it's not straightforward as antibody production is dependant on the age of the host plus sometimes other factors.