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FDA just cleared a $20 Covid-19 antibody test

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Re: FDA just cleared a $20 Covid-19 antibody test

#41

Post by cma »

product50 wrote: post #32
jupp0r wrote: post #24

> The sensitivity is 97.90 %, the specificity is 91.77%. This seems like it could provide a false sense of security to many if used widely by the general population.

Some smart ass always has to comment how this is not perfect and thus not useful. Look at the alternatives. Should we just keep on waiting otherwise?

It is probably useful for getting population statistics and directing higher level actions, or even at some point overquarantining people based on positives and false positives, but people that get a false sense of security are a risk. There was an article about a village leader who tested negative and had 200 villagers come to congratulate him, then he tested positive on a subsequent test.

Re: FDA just cleared a $20 Covid-19 antibody test

#42

Post by throwaway2048 »

erentz wrote: post #34
baybal2 wrote: post #5

That's an antibody test, not an RNA test. Quite a different thing. It will only detect an infection when you have an immune response already. It will not if you don't. RNA tests can detect the virus even if it doesn't turn a person diseased.

One reason people seem to be missing for why antibody tests are very useful is it will allow us to confirm those that are now immune. We can’t get this from the RNA testing because it’s primarily being used on only symptomatic people at the time they have symptoms (and then only if they can get the test which typically means severe symptoms) But if we start to test widely for antibodies we can start to clear people f…

There is evidence that people can become re-infected, so antibodies aren't enough.

Re: FDA just cleared a $20 Covid-19 antibody test

#44

Post by maxerickson »

CreepGin wrote: post #25
adrr wrote: post #16

Earlier quoted context omitted.

It's important to test the public to see the penetration into the population. People who test positive should get an RNA test to determine if infected. People who are not infected become valuable assets to keep logistics and supply chain up and work front line tasks as they have little risk of getting infected. This group people can return back to normal life and don't need to be lockdown.

I can't help but ask... How much risk is "little risk" here? Can they still contribute to the spread? And what percentage of population can fall into this group?

We don't know.

The period of immunity following infections varies, and this virus is not well understood.

Re: FDA just cleared a $20 Covid-19 antibody test

#45

Post by absherwin »

This is an antibody test which will only be positive days after the onset of symptoms.

This is principally useful for several purposes:

1. Figuring out who to isolate in hospitals if the RNA test isn't available in sufficient quantity

2. Understanding who has already recovered from COVID-19 and is thus immune with all that implies in terms of inability to spread the disease and reduced need for PPE

3. Enabling us to confirm continued immunity later this year and understand how long the recovered will remain immune

This is not unique to this company. It's unclear to me whether the price is meaningfully less than competitors.

This thread is helpful for further understanding of the test and its utility: https://twitter.com/NAChristakis/status/1240689953895411714

Two more helpful references: State of testing techniques as as of a week ago: https://sph.nus.edu.sg/wp-content/uploads/2020/03/COVID-19-S...

The paper on which this test is based: https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmv.25727

Re: FDA just cleared a $20 Covid-19 antibody test

#46

Post by cactus2093 »

baybal2 wrote: post #5

That's an antibody test, not an RNA test. Quite a different thing. It will only detect an infection when you have an immune response already. It will not if you don't. RNA tests can detect the virus even if it doesn't turn a person diseased.

I don't know how much precedent there is for this type of testing (have we used similar things for Ebola or SARS or measles or anything else?).

I've read that this will be useful in broad studies to track how widely the disease might have spread without being diagnosed. But will this type of antibody test eventually be available for any doctor to order for a patient? I'm just getting over a fairly mild but persistent chest cold which also had me with a slight fever last week, and would really like to know if it is/was covid-19 or not. Last week when I still had the worst of the symptoms, my doctor said I didn't meet enough of the criteria to be tested.

Re: FDA just cleared a $20 Covid-19 antibody test

#47

Post by mikeha »

jupp0r wrote: post #24

> The sensitivity is 97.90 %, the specificity is 91.77%. This seems like it could provide a false sense of security to many if used widely by the general population.

And also this.

>Positive results may be due to past or present infection with non-SARS-CoV-2 coronavirus strains, such as coronavirus HKU1, NL63, OC43, or 229E.

Re: FDA just cleared a $20 Covid-19 antibody test

#48

Post by gridspy »

absherwin wrote: post #45

This is an antibody test which will only be positive days after the onset of symptoms. This is principally useful for several purposes: 1. Figuring out who to isolate in hospitals if the RNA test isn't available in sufficient quantity 2. Understanding who has already recovered from COVID-19 and is thus immune with all that implies in terms of inability to spread the disease and reduced need for PPE 3. Enabling us to…

Bear in mind in relation to immunity -- "Positive results may be due to past or present infection with non-SARS-CoV-2 coronavirus strains, such as coronavirus HKU1, NL63, OC43, or 229E."

Re: FDA just cleared a $20 Covid-19 antibody test

#49

Post by xsmasher »

throwaway2048 wrote: post #42
erentz wrote: post #34

Earlier quoted context omitted.

One reason people seem to be missing for why antibody tests are very useful is it will allow us to confirm those that are now immune. We can’t get this from the RNA testing because it’s primarily being used on only symptomatic people at the time they have symptoms (and then only if they can get the test which typically means severe symptoms) But if we start to test widely for antibodies we can start to clear people f…

There is evidence that people can become re-infected, so antibodies aren't enough.

Citation?

I saw the one story about people "testing positive again" but that seemed to be a testing abnormality, not people getting sick a second time.

Re: FDA just cleared a $20 Covid-19 antibody test

#50

Post by codyb »

CreepGin wrote: post #25
adrr wrote: post #16

Earlier quoted context omitted.

It's important to test the public to see the penetration into the population. People who test positive should get an RNA test to determine if infected. People who are not infected become valuable assets to keep logistics and supply chain up and work front line tasks as they have little risk of getting infected. This group people can return back to normal life and don't need to be lockdown.

I can't help but ask... How much risk is "little risk" here? Can they still contribute to the spread? And what percentage of population can fall into this group?

I think if you test positive with an antibody test but not an rna test it means your immune system has the ability to fight it off from a previous infection but the virus isn’t currently multiplying inside you.
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