# Antibody testing to begin next week



## Brendan Burgess (21 May 2020)

Of random samples, in two areas of the country to determine the prevalence of Covid-19 generally.









						Coronavirus: Ireland to start antibody testing early next month
					

Test can detect if person has had Covid-19 and can determine prevalence in population




					www.irishtimes.com


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## Brendan Burgess (21 May 2020)

How reliable is the antibody test? 

Can I go somewhere and get the test? 

I know that it's no guarantee of immunity, but it would be reassuring to know that you did have it and have probably built up some immunity.

Brendan


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## Sunny (21 May 2020)

I presume you can volunteer but I am guessing it will be controlled to ensure they get a proper selection of the population.


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## losttheplot (21 May 2020)

A recent study in Stockholm showed just 7% had antibodies by the end of April. They were expecting 30%.

Roche and Abbotts lab based blood tests claim close to 100% sensitivity (ability to detect positive samples as positive) and greater than 99% specificity (ability to detect negative samples as negative).


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## Baby boomer (21 May 2020)

What's the danger of a false positive for antibodies?  This could lead inadvertently to very risky behaviour for the tested person and his/her contacts.


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## Brendan Burgess (22 May 2020)

Good explanation of it here but it's from the 8th May with the Biomednomics test.  (More recent tests may be more reliable) 









						How to understand Covid-19 antibody testing in 10 steps
					

Inaccuracies in the testing, such as false negatives and false positives, are potentially harmful




					www.theguardian.com
				




For those who suspect that they had it

18% false negatives
13% false positives





losttheplot said:


> Roche and Abbotts lab based blood tests claim close to 100% sensitivity (ability to detect positive samples as positive) and greater than 99% specificity (ability to detect negative samples as negative).



If these figures are accurate, the Guardian article needs to be rewritten.

Brendan


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## Brendan Burgess (22 May 2020)

I had mild symptoms back in March.  I don't know if I had it or not. 

If I could do a Roche test with 100% correct positivity, I would certainly do it.

*If I get a positive result, what are the implications? *

1) There is a 99% chance that I had Covid.
2) I have probably built up some immunity 
3) But I am not completely immune 
4) I will continue to be cautious until there is a vaccine. 
5) I will continue to keep an eye out for symptoms e.g. fevers or coughs. 

I will certainly visit friends and go into their houses which I am not doing at present. 
I would go to a restaurant or pub with seating
I would definitely cycle and drive further. The thing I miss most is walking in the mountains. 
I don't need to attend any mass gatherings, so I won't. 
If I were allowed to travel abroad, I would probably do so. But it would not be essential, so, on reflection, I probably wouldn't. 


*If I get a negative result *
1) There is a 99% chance that I have no immunity 
2) So I would continue to be very careful

*But it depends on personal circumstances *
I am retired so I don't need to commute to a working environment with other people.


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## RichInSpirit (22 May 2020)

I for one would like to know if I already caught the Covid-19. 
I would pay for my own antibody test. Provided that it was under €10 or €20. And not €150 or more like the official test up to now.
I was abroad in early January and had a bit of a cough and sniffles when I came home for a couple of days. I was blaming it on bad beer.


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## Purple (22 May 2020)

losttheplot said:


> A recent study in Stockholm showed just 7% had antibodies by the end of April. They were expecting 30%.


Does that mean the disease is far less contagious than previously thought or are Sweden's control measures effective (or both)?


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## losttheplot (22 May 2020)

Brendan Burgess said:


> Good explanation of it here but it's from the 8th May with the Biomednomics test.  (More recent tests may be more reliable)
> 
> 
> 
> ...


I think the Guardian article is only considering the rapid tests. 

I think the intention of antibody testing is more for a snapshot of the overall population rather than for the individual. For mass population testing, sensitivity below 99% would probably be no use.








						Covid-19 antibody tests face a very specific problem
					

With the prevalence of coronavirus infection running at about 5%, test manufacturers and regulators alike will have to guard against false positives.




					www.evaluate.com
				



As the prevalence of the disease is quite low, the overall false positives would be high.


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## losttheplot (22 May 2020)

Purple said:


> Does that mean the disease is far less contagious than previously thought or are Sweden's control measures effective (or both)?


It could be both. It knocks the herd immunity approach back, they were expecting a much higher infection rate.


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## losttheplot (22 May 2020)

RichInSpirit said:


> I for one would like to know if I already caught the Covid-19.
> I would pay for my own antibody test. Provided that it was under €10 or €20. And not €150 or more like the official test up to now.
> I was abroad in early January and had a bit of a cough and sniffles when I came home for a couple of days. I was blaming it on bad beer.


The lab based test cost are being estimated between $25-$50. This would only be the cost of the test. Additional cost would be taking the blood sample, transport etc. Costs would go down as volume goes up.


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## Purple (22 May 2020)

Roche, Abbott Siemens are now all offering antibody testing (Siemens claim theirs is the best) so most of the big boys are in the game. Expect prices to drop.


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## XMarks (23 May 2020)

Abbot tests are more accurate up to 40 days since suspected infection.
Roche tests are more accurate after 40 days since suspected infection.
The wholesale cost of these tests (not including lab work) is about €6.

Brendan, there is a company in Dublin offering the test. The name escapes me. They were advertising on google ads last week.  They were charging €120. Their ad is not coming up now but they may disable ads over the weekend. I got an antibody test from the UK.


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## XMarks (23 May 2020)

Brendan Burgess said:


> *If I get a positive result, what are the implications?*



South Korea released a report on a study last week that showed people were most likely immune from re-infection. The report is awaiting peer review. 









						New data suggest people aren’t getting reinfected with the coronavirus
					

People who recover from COVID-19 but later test positive again for the coronavirus don’t carry infectious virus, a study finds.




					www.sciencenews.org


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## Brendan Burgess (23 May 2020)

Great article on the topic in the FT by _David Crow is the FT’s US coronavirus correspondent_









						Will antibody tests be our passport to normality? | Free to read
					

David Crow on the complications — and consequences — of testing for coronavirus immunity




					www.ft.com
				




I think that the FT is making its Coronavirus stuff free to read. 


_“The hope was that we’d roll out the testing, find lots of people with antibodies, infer many people are immune, and we can start going back to our regular lives,” says Lloyd Minor, dean of Stanford University’s school of medicine. “By anyone’s measure, we’re nowhere close to that.” 

...

Given all the uncertainty, it is perhaps unsurprising that many public-health experts have greeted the arrival of antibody tests with scepticism. Some fear that people who do test positive for antibodies will start behaving irresponsibly and stop adhering to blunt but effective measures such as lockdowns and social distancing that have managed to slow the spread of the disease. “If you test positive for IgG, I don’t think there is any science out there that says you don’t have to follow the rules,” says Dr Rajiv Shah, who ran the US Agency for International Development between 2010 and 2015 before becoming president of the Rockefeller Foundation. “If we start using the results in a way that’s not backed up by science, people could end up doing some risky things. It is not a licence to do anything that you’re not already allowed to do.” _


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## Purple (28 May 2020)

I can't find any recent data on testing figures. Did the HSE get to their figure of 100,000 tests per day by the 18th of May?


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## Ceist Beag (28 May 2020)

I believe the figure was 100,000 tests per week Purple, not per day. And yes they are saying they have the capacity now to achieve this (source https://www.irishexaminer.com/break...-tests-showing-negative-says-hse-1001428.html) but I don't think they are actually carrying out anything like this number of tests per week currently.


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## Purple (28 May 2020)

Some good news about resistance and immunity levels. Those who were exposed to SARS still show high levels of reactive T-Cells 17 years later and those T-Cells also protect from Covid19. It was also found that about 50% of those examined who were never exposed to SARS or Covid19 had high levels of resistive T-Cells. In other words there seems to be a high levels of natural resistance to Covid19 in the general population.


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## Drakon (2 Jun 2020)

My wife is being antibody tested. There are three separate tests:
Pin-prick
**************************
ANOther

She’s had the pin-prick test.The results came back within an hour. She tested negative for antibodies. There were 49 others tested that day. They all tested negative.

When she was sick with the virus she was ill for 15 days. I’ve read that you need to be sick for 10 days or more to develop antibodies and that’s why the very mild cases have zero antibodies and there have been re-infection cases.

I think they’re focussing on those that tested positive for C19 first, then their close contacts. I’ve been lined up (I had the bug but wasn’t tested for it) for the test but it could be a few weeks.


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## Drakon (2 Jun 2020)

Dunno why the word ************************** got asterisked out there?


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## Drakon (2 Jun 2020)

Phonetically the word is SEE-rum


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## Drakon (2 Jun 2020)

Purple said:


> Does that mean the disease is far less contagious than previously thought or are Sweden's control measures effective (or both)?


The control measures in most countries has made it less contagious, possibly?

With 40% of households in Sweden being single-occupancy, it’s hard to assess any data out of that country.


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## Drakon (2 Jun 2020)

RichInSpirit said:


> I was abroad in early January and had a bit of a cough and sniffles when I came home for a couple of days. I was blaming it on bad beer.


Was it a dry cough, completely dry?
“Sniffles” suggests it wasn’t C19
Two days for an adult definitely suggests it wasn’t C19.


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## EmmDee (2 Jun 2020)

Purple said:


> Does that mean the disease is far less contagious than previously thought or are Sweden's control measures effective (or both)?



Sweden's death toll is about a third higher than ours (per mm of population) and have been trending back up over the last 10 days. Current 7 day rolling average is about 4 times ours (per mm population)


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## IsleOfMan (2 Jun 2020)

Drakon said:


> My wife is being antibody tested. There are three separate tests:


Who is organising the tests for you both?


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## Drakon (2 Jun 2020)

IsleOfMan said:


> Who is organising the tests for you both?


Her employer. She’s a nurse working in clinical trials.


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## Drakon (2 Jun 2020)

Brendan Burgess said:


> 4) I will continue to be cautious until there is a vaccine.



Are you confident there will be a vaccine?
It took four years to develop the vaccine for mumps, and that’s the fastest vaccine in terms of development time. 
The chicken pox vaccine took 28 years.

The common cold is the most common and most widespread disease in the world. It is a Corona virus. And there is still no vaccine for that. And even if there was one, the colds antibodies are only active in the body for six months or so.

I won’t make any decisions based on a vaccine.


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## Purple (3 Jun 2020)

Drakon said:


> The common cold is the most common and most widespread disease in the world. It is a Corona virus.


The common cold is actually about 200 different viruses. Most of them are rhinoviruses but some are coronaviruses.

I agree with your point about vaccines; 17 years later and there's no vaccine for SARS, although it kind of just went away so there's no big push to develop one.


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## Ceist Beag (3 Jun 2020)

Just out of curiosity, I have heard Covid-19 referred to as SARS 2 by a number of prominent people recently (Prof Sam McConkey being one), is this being done to reinforce the fact that no vaccine may be found? For months now we have been used to having it called Covid-19 so I'm just curious as to why they are now calling it SARS 2 - it is clearly being done intentionally for some reason.


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## Leo (3 Jun 2020)

Ceist Beag said:


> I' m just curious as to why they are now calling it SARS 2 - it is clearly being done intentionally for some reason.



It's a clarification in terminology really, The name hasn't changed, COVID-19 is the official title of the disease, SARS-CoV-2 is the virus that causes it.


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## Drakon (3 Jun 2020)

SARS was too lethal for its own existence and killed off its hosts too quickly, rendering it not a concern.
I think this is the reason the SARS vaccine still hasn’t been invented. 
HIV/AIDS is another high profile viral infection for which there is still no vaccine. 30+ years later.


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## Purple (3 Jun 2020)

Drakon said:


> SARS was too lethal for its own existence and killed off its hosts too quickly, rendering it not a concern.
> I think this is the reason the SARS vaccine still hasn’t been invented.
> HIV/AIDS is another high profile viral infection for which there is still no vaccine. 30+ years later.


SARS was far less contagious and far more fatal. The other major factor in its containment was that the level of trade between South East Asia and the USA and Europe was 1 20th of what it is now.
The vast majority of funding for vaccines is from private for profit sources. HIV/AIDS is a hard disease to develop a vaccine for and those at high risk are poor so the market isn't there relative to the risk/costs. The vast majority of public funding globally comes from the US Government but it still isn't anywhere enough.
_Edit: I presume that being an RNA virus Covid19 stays in the cytoplasm of the cell, unlike AIDS which is a DNA virus and so enters the DNA of the host and integrates with their Genome (that's all I remember on the topic from my Leaving Cert Biology)._ 
It still kills about a million people a year but most of them are poor and black so rich Western countries don't care... other than the USA who provide 80% of the public funding for research and fund subsidised treatments in sub-Saharan Africa (thank you George W Bush and Bono).


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