cPass New Antibody Test

Good morning- There isn't any antibody test that detects the presence of the SARS-CoV-2 virus to diagnose COVID-19.These tests can return a negative test result even in infected patients (for example, if antibodies have not yet developed in response to the virus) or may generate false-positive results (for example, if antibodies to another coronavirus type are detected), so they should not be used to evaluate if you are currently infected or contagious (ability to infect other people).

Antibody tests for COVID-19 are currently available. Northwestern University in Chicago and Mt Sinai School of Medicine in New York have used SARS-CoV-2 IgG antibody tests in their research to identify people who have either had or were exposed to the virus and recovered. Results from Northwestern's SCAN research studies have already been published..These tests have been developed to be very specific for COVID-19, although there is always a very remote chance that they may detect previous infections with other similar coronaviruses.The basic science of antibodies is that once you are infected, your antibody levels will go up soon after infection and gradually decline over time. The immune system has memory cells that will reactivate if you are exposed to the same (or possibly similar) virus or infection again, and it should again produce antibodies to protect you. Antibody tests for Covid-19 are also available from commercial labs such at Quest Diagnostics. No, they shouldn't be used to diaginose an active infection, but they can be useful to tell someone whether they've had the virus and developed an antibody response to it. The problem is, you have to test at the right time. You could show negative if you test too soon after infection, or if if you wait too long after having recovered, because your antibodies may have already declined to the point of nondetection. Depending on the antibody test used and the lab that processes it, they will report the results as qualitative (ie, the antibody is "present or not present") or quantitative (whereby the actual level of the antibody is reported).

"quantitative (whereby the actual level of the antibody is reported)." Which tests show the quantitative results. That's all I'm asking. Thanks.

I think you would need to contact each lab that offers the tests. Also, you need to be aware that the quantitative results change over time. My friend had Covid & was donating convalescent plasma each month. Her antibody levels were tested before each donation and at 6 months, the fell to undetectable.

May I ask why you are seeking a quantitative test?
Sue

The antibodies that show up in our blood are not the ones that we all want to know about and that is the number of antibodies (quantitative) that count for protection. If I'm wrong about what you are asking, I apologize.

The SARS-CoV-2 spike protein test is used to check for antibodies for the vaccines for Covid 19. It only shows whether there are antibodies in the blood, specifically IgM/IgG spike proteins which could be either from direct exposure to Covid-19 or from the vaccination. Having the antibodies is a good sign but it does nothing to directly tell us the level of our immunity to the virus.

Because of this the "quantitative (whereby the actual level of the antibody" can not be reported as there is no test as yet that has been approved for testing this, or perhaps in existence.
.
https://www.labcorp.com/coronavirus-disease-covid-19/providers/antibody-test

There may be more than one type of antibody is involved (as is the case for flu, for instance) and they might not know if they exist at this time. There are many processes involved in testing the quantitative levels of antibodies and variants certainly change things. There just hasn't been enough time that has passed to answer this. This is a very simple answer to a very complex question and process. Perhaps @sueinmn has more information for you

Does this make sense?

Yes. It does make sense. The only reason it should concern immunocompromised patients is that we are all want to know -- beyond the "yes" I have antibodies from exposure or the vax -- is WHAT LEVEL DO I HAVE? The research studies from Paris and Toronto, I've posted on here earlier, mentioned specific percentages. For example, 40% or 55% or less than 11%. So I'm just curious scientifically as to how they can be so specific and other people are saying the tests don't exist. It's confusing as with everything in this Covid19 era. But you've made given a reasonable explanation.

I'm curious too. Have you checked their specific testing methods and what they are testing? I agree, there has been only confusion. Tests such as we are discussing have to be approved by the FDA (I think that I said the CDC before and that is wrong) and there aren't any here. Maybe in other countries, they have different testing processes and departments.

Hello everyone- I too want to know how protected I am in NUMBERS against the virus or covid vaccine. 100% or less than 50%. However, there still seem to be many different angles to this question being asked. As yet there are no tests that give a quantitative measure, one that tells us this, just if we have antibodies.

This is exactly what the FDA says:
https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-first-test-detects-neutralizing-antibodies-recent-or

The cPASS neutralizing tests use a different principle in their testing: So how does it work?

"It uses a different principle," says Wang. "We don't detect the antibody itself, but instead we check the blood for anything which blocks the binding of the virus [spike protein] to the hACE2 receptor on human cells. It's a functional assay that specifically looks for the neutralizing antibody."

At the moment, the company can't say for sure that this test—even if it detects neutralizing antibodies—guarantees immunity against reinfection with Covid. That still requires further research. However, the test could offer a vital step when trying to figure out our current levels of herd immunity, for example, or whether that's even achievable without a vaccine. When a vaccine does come along, it can also help show whether it is effective.

"We need something to test whether the people who receive vaccinations generate neutralizing antibodies," Wang explains. "And not just any antibody. It has to be the neutralizing antibody."

It's neutralizing antibodies that will offer long-term protection against Covid, stopping the disease before it can take hold.

Unfortunately, not one test can currently give us any assurance of that. We know from related coronaviruses, such as those which cause the common cold, that immunity is often very short-lived, and people can be reinfected with the same virus." GenScript John Cumbers et al. A New Test May Show Whether Your Immune System Can Neutralize The Coronavirus. [Article]

I hope that this clears things up!

The test I was given at Mayo is SARS-COV-2 SPIKE AB, SEMI-QUANT,S
Component Results: Interp. S = Positive
Quant, S = 561 U/ml
I know several people who have had this test done here at Mayo. Numbers vary but all were vaccinated early in the year.
Sorry if this does not help here......

This is what this tests shows, so that you know for yourself:

Test Details
Use

Qualitative and semi-quantitative detection of antibodies to SARS-CoV-2 spike protein receptor-binding domain (RBD). Aid in identifying individuals with an adaptive immune response to SARS-CoV-2, indicating recent or prior infection. At this time it is unknown how long antibodies persist following infection and if the presence of antibodies confers protective immunity. The performance of this test has not been established in individuals that have received a COVID-19 vaccine. The clinical significance of a positive or negative antibody result following COVID-19 vaccination has not been established and the result from this test should not be interpreted as an indication or degree of protection from infection after vaccination.
Limitations

This test should not be used to diagnose or exclude acute SARS-CoV-2 infection. The results should always be assessed in conjunction with the patient's medical history, clinical presentation, and other findings. A negative test result does not rule out the possibility of an infection with SARS-CoV-2. Serum or plasma samples from the very early (pre-seroconversion) phase can yield negative findings. Therefore, this test cannot be used to diagnose acute infection. It has also been reported that certain patients with the confirmed infection do not develop SARS-CoV-2 antibodies. Furthermore, the waning of antibody titers has been reported in some individuals within a range of months after infection, a feature which has also been reported for other coronaviruses.

This test has not been FDA cleared or approved. This test has been authorized by FDA under an Emergency Use Authorization (EUA). This test is only authorized for the duration of the declaration that circumstances exist, justifying the authorization of emergency use of in vitro diagnostics for the detection and/or diagnosis of COVID-19 under Section 564(b)(1) of the Act, 21 U.S.C. 360bbb-3(b)(1), unless the authorization is terminated or revoked sooner. This test has been authorized only for detecting the presence of antibodies against SARS-CoV-2, not for any other viruses or pathogens.
Methodology

This test shows only detects that you have antibodies, but not the significance of the number or what the number means.