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Coronavirus

Antibody test

(24 Posts)
Teetime Thu 29-Oct-20 09:49:51

I received an antibody test in the post yesterday as I had agreed to take part in a research programme. It was negative. I hoped it would be positive because I really feel I had the virus in the early spring. However I do realise that the negative results doesn't necessarily mean anything I could have had antibodies and they have disappeared.

MissChateline Thu 29-Oct-20 09:52:48

I too was convinced that I had the virus in March this year. I asked for an antibody test when I had my pneumonia vaccination and they did one the following day. This also came back as negative. I still have no idea whether I’ve had it or not.

PECS Thu 29-Oct-20 09:57:15

And a friend of mine who has not even had a sniffle had her ( random sample) anti body test come back positive. She is desperately trying to think where she has been etc. as she has taken huge care and was shielding for mpnths until joining her DDs family bubble!

MissAdventure Thu 29-Oct-20 10:00:34

Mine was negative, too.
The wording was that it's "unlikely" that I have had the virus.
I have read that antibodies can disappear within 3 months of having corona, particularly in older people.

So, it does seem a bit of a shot in the dark.

Teetime Thu 29-Oct-20 10:14:10

I dont think the tests are totally reliable either there is probably a percentage of false negatives and false positives as there are with many such tests.

EllanVannin Thu 29-Oct-20 10:21:31

No antibodies would be detected in your blood if no infection is present or even has been. Only if you feel or are unwell at the time would antibodies show up and even then a test for the infection would have to be done separately. It could also produce a false negative too.

Illte Thu 29-Oct-20 11:39:00

That can’t be right, can it EllenVannin? You can pass your antibodies to your unborn baby, after all, from infections you had as a child. They must still be in your blood.

I’m willing to learn though if you medical knowledge otherwise.

M0nica Thu 29-Oct-20 11:49:35

The results of an antibody research survey (probably the one Teetime was part of) were announced yesterday. They reported that antibodies remained in the body for months after infection, but did seem to tail off, so that hopes that an attack would give immunity for life have been dashed.

When a vaccination is available, like flu, it will need to be renewed annually.

Illte, You must be right, if you have illnesses like measles, Whooping cough, or receive jabs like the BCG the immunity is long lasting, decades, if not lifelong.

EllanVannin Thu 29-Oct-20 13:31:23

Illte antibodies will only remain in the blood while the infection is present. As in Covid, it's only present for a couple of months. Antibodies passed through to a foetus only happens during the last 2 or 3 months of pregnancy in the form of immunity and not because there happens to be an infection in-situ. It's the way the system works preparing for immunity.
Childhood illnesses don't always deem immunity in later life as antibodies aren't a life-long thing. They're only present when infection strikes.

ElaineI Thu 29-Oct-20 13:37:02

DD1 has been selected for an antibody test. They seem to be checking teachers in Midlothian in this survey.

GagaJo Thu 29-Oct-20 13:37:58

I had an antibody test in March. Negative. Still, I'd have lost those antibodies by now so...

B9exchange Thu 29-Oct-20 13:44:28

Daughter had one some months after her infection at the beginning of February. She still has parosmia (altered sense of taste and smell) after all those months, GP and ENT consultant both convinced she has had it, but her antibody test came back negative, whereas her husband, who caught it from her and wasn't exposed to anyone else, came back positive. The latest study didn't look at T cell immunity, so a bit of a gap in the research there.

MissAdventure Thu 29-Oct-20 13:44:33

I always understood that antibodies remain after an infection.
Not that I know anything much.
Either way, it does seem fairly useless, does anyone think, aside from me?

Illte Thu 29-Oct-20 15:24:08

Wow. I’ve just done a 19 minute learning session on the Internet.

My apologies to EllanVannin, your difiable antibodies are only there for a limited time.

Now I know about antibodies and t-cells and memory something or others.

I’d try to explain what I found out but Id do it badly. It seems that the actual antibodies go but leave a memory of the infection so your immune system can kick back in if it recognises it again.

I think.🤷🏼‍♂️😬

Illte Thu 29-Oct-20 15:24:54

10 minute learning session.

My concentration isnt that good!

Phloembundle Fri 30-Oct-20 10:23:23

Waste of time and money.

polnan Fri 30-Oct-20 10:53:21

I don`t trust most of these "tests" statistics.. etc.. mind you think perhaps I don`t trust some of the Government or its advisors... now what is that saying? statistics, statistics....... praps my mind is inventing something, or trying to.

Aepgirl Fri 30-Oct-20 11:10:23

It’s all such a new virus that there are bound to be discrepancies. However, without these tests we will never get a safe and reliable vaccine.

Authoress Fri 30-Oct-20 11:14:49

I'm pretty certain I had CV in March. A blood test based antibody test last month said that I had a count of 64 of whatever they measure, and immunity was 70. Close but no cigar...
My sister is on a long-term trial, an antibody test every month; she thinks she had CV in February, and her test (a pregnancy test style drop of blood, wait for lines to appear) JUST had a faint line for one kind of antibodies this month.
My sister had a thankfully mild shot at the disease, and although I was sicker, I didn't have to go to hospital.

crazygranny Fri 30-Oct-20 11:27:09

An MP who had a particularly bad covid experience was donating plasma in the hope of helping others with her antibodies. Her plasma is no longer collected as all trace of antibodies has vanished.

Autumnrose Fri 30-Oct-20 12:30:23

Because I had COVID in early March an antibody test was added to my recent routine NHS blood tests. It came back negative with the comment “ no serological evidence of SARS-CoV-2 infection, however it is possible that available serological tests may not detect antibodies in a minority of people. Consider as susceptible.” The gap of seven months between the illness and antibody test does rather suggest that immunity is short lived and this does of course have implications for how we will live with COVID in the future.

Pudding123 Fri 30-Oct-20 14:18:14

I had no symptoms but lost my taste and smell in March( which I have still not regained)I did an antibody test 2 days ago and it was positive ,it stated that although the antibodies were still in my blood I could catch covid again so to still follow all the gov guidelines

Floradora9 Fri 30-Oct-20 16:38:49

My DS is sure he had the virus as he sat beside someone at work who tested positive and he was pretty ill. He recently had to have a medical and it showed he had no antibodies to the virus.

LJP1 Sat 31-Oct-20 07:56:20

This is a bit out of date now but gives the background to the antibody test:

imperialbrc.nihr.ac.uk/2020/08/19/largest-study-on-home-coronavirus-antibody-testing-publishes-first-findings/

or

www.medrxiv.org/content/10.1101/2020.07.14.20151126v1

For long term immunity, memory T & B lymphocytes are needed and we do have to length of experience yet, to test for them but the antibody test we do have are over 90% reliable..