Will this test tell me if I’ve been infected with SARS-CoV-2 virus?
Yes, especially, if the exposure/infection happened over 2 weeks ago. Early studies suggest the production of IgM and IgG antibodies in COVID-19 patients typically occurs between 7 to 11 days after exposure, with IgM antibodies appearing first, followed by IgG antibodies. In a small percentage (<1%) of the positive results are due to unrelated Coronaviruses which can cause the common cold-like symptoms. Hence, these unrelated coronaviruses such as 229E, NL63, OC43, and HKU1 can cause a “false” positive test.
Will this test tell me if I’m still infectious, especially if I’m asymptomatic?
Maybe. The IgM antibody appears as early as day 5-7 and there may not be a viral load strong enough yet to cause symptoms of COVID-19.
By knowing if I’ve got antibodies for IgG, does this mean I’m not infectious?
Maybe. And the answer is more likely YES, if you only show IgG antibodies and no IgM antibodies.
What does it mean to test positive for IgG antibodies only?
It means that you have likely been exposed to a coronavirus, even in the absence of symptoms from the infection. These viruses can include SARS-Cov2 (causes COVID-19).
How much immunity do I have if I test positive to IgG antibodies?
We simply don’t know yet as this virus is new. But we believe it will give you some degree of protection should you be re-infected, assuming you did indeed get infected with SARS-Cov2 (Covid-19). How much immunity you have will depend on how much natural antibodies you’ve developed to fight off another round of infection.
Why is WHO saying they cannot confirm that having antibodies will protect you from another bout of infection?
Your antibodies have been developed for one COVID-19 strain that you were exposed to. We are aware that this virus has mutated over 250 times to date. Hence, if you become exposed to a newer strain, that is not genetically close enough to the old strain, your antibodies will be less effective against this newer strain.
This is a similar analogy to the Influenza A virus. We need to get flu shots annually to develop immunity against a ‘new strain’.
How often should I do this test?
For active screening, we encourage repeating this test every 4-8 weeks, to ensure that we capture the antibodies levels in real time against exposure risks and also benefit from improved ELISA testing plate performance.
Your kit will contain all the necessary supplies for self-collection in the comfort of your own home. The test only requires 4 drops of blood. You will collect your blood sample using the HemaSpot-SE™ device included in your kit.
• Easy self-collection of your blood sample
• Reduces risk of exposure to yourself and others, using the privacy of your own home
• Eliminates the use of Personal Protective Equipment (PPE), as there is no need for a lab tech
• Results received within 48-72 hours upon arrival to lab via a secure HIPPA compliant portal
• Professional analysis by CoreMedica, USA a CLIA licensed and CAP Accredited Laboratory
Drop™ COVID-19 Antibody Testing
The Drop™ COVID-19 Antibody Test performed by CoreMedica in the United States uses the gold standard ELISA (enzyme-linked immunosorbent assay) technique adapted to a dried blood format.
Although this testing method is the laboratory standard, there will be constraints with the ELISA plate performance given these types of antibodies-antigen plates are new to the marketplace. The overall sensitivity and specificity will improve as more testing is done with time. At present, the plates are performing specificity greater than 99.8% and sensitivity of 100% sensitivity and specificity. It is FDA approved as of May 2, 2020.
What makes this test distinctive is that you can perform it yourself, without the need to go to a laboratory, where the technician does a blood draw and sends one tube of your blood for processing.
Compared to a traditional blood draw sample, the Drop™ COVID-19 Antibody Test is collected in a dried blood format. This technique has been validated to be equal in sensitivity and specificity to a standard blood draw.
Immune Response to the Infection
Using a small blood sample, this test helps to detect recent past exposure to the SARS-CoV-2 virus by measuring the immune response to the infection. This is done by identifying IgM and IgG antibodies using the ELISA (enzyme-linked immunosorbent assay) laboratory methodology.
Clinical sensitivity and specificity were determined by testing paired serum and dried blood specimen samples containing variable levels of IgG/IgM antibodies.
Compared to a traditional blood draw sample, the Drop™ COVID-19 Antibody Test has been validated to be equal in sensitivity and specificity.
Test Accuracy is Unclear
At the moment, the true accuracy of RAPID serologic tests for SARS-CoV-2 is under review. There are certain concerns that it is not sensitive nor specific enough to provide scientifically sound results.
In contrast to the gold standard ELISA methodology, these ‘Rapid’ Screening tests in the open market developed and manufactured outside of North America use a LFIA (lateral flow immunoassay) methodology.
Recently, the authenticity of these RAPID testing kits cannot be guaranteed. Just as what has happened in the masks market, its now happening in the self-testing market.
Measured against the ELISA test, the LFIA method is far less sensitive (false negative rate) and not completely specific (false positive rate).
The best way to explain this is if you’d be willing to have a home pregnancy test that gets your result wrong up to 5-20% of the time, which is a false negative. As well, most of these tests have a 5% error rate to say you are pregnant when you’re really not pregnant.
Challenges of COVID-19 Testing
Dr. Sanjay Gupta, Chief Medica Correspondent, CNN
Canadian Antibody Testing Report
Avis Favaro, Medical Correspondent, CTV National News
The DropTM COVID-19 antibody test performed by CoreMedica, established in 2020 in Lee’s Summit, Missouri, USA, specializes in minimally invasive testing. CoreMedica is a CLIA licensed and CAP Accredited Laboratory.
CoreMedica’s SARS-CoV-2 virus IgG and IgM antibody test is under the regulatory jurisdiction of the U.S. Department of Health and Human Services who enforces the Clinical Laboratory Improvement Amendments (CLIA) program. Any organization must have a CLIA certificate in order to provide clinical laboratory services in the United States. The CLIA program is administrated by the Centers of Medicare and Medicaid (CMS), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA). PEUA200459
The ELISA testing methodology used by CoreMedica for antibodies detection does not require Health Canada approval because the test is completed using a standardized laboratory technique in a licensed laboratory in the United States and ordered by a licensed Canadian physician.
Dry Blood Spot Collection Device
The HemaSpot-SE Blood Collection and Transport Device is listed with the FDA as a Class I device (general controls), Product Code: NNK, and under 21 CFR 864.3250. This device is exempt from the premarket notification and does not require FDA approval.
In Canada, CoreMedica has filed their HemaSpot-SE™ Collection Device with Health Canada and are awaiting approval that this device meets the health and safety standards of Health Canada to collect blood drops. Therefore, blood collection using the HemaSpot-SE™ Collection Device in Canada will be performed under physician supervision until this device is approved by Health Canada.