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Antibody FAQ



We are proud to offer the most accurate Covid Antibody testing in the marketplace today!  

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What are antibodies?

Your body produces antibodies to help protect you from future infections. 

Antibodies are blood proteins produced by your body’s immune system to neutralize pathogens such as bacteria and viruses.  The protein recognizes a unique molecule of a pathogen and prevents that molecule from functioning.  In the case of Coronavirus, antibodies may bind the spike (s) proteins, and cover the virus.  By attaching to the spike protein, it may prevent the virus from attaching to your cells, preventing infection.  There are three main antibody types, and some appear earlier than others.  IgM is a short-term antibody, which can be produced in large amounts early in an infection, IgG is and antibody produced for longer term protection (part of your immune system memory), and IgA is an antibody usually found in mucus secreting tissues such as the gt, respiratory tract and saliva.    

What is the antibody testing for?

To help determine if you have been infected in the past and possibly carry protection from future infections. 

Antibody testing determines if you have developed antibodies against parts of the SARS CoV 2 virus.  This means you have been exposed to SARS CoV 2 in the past, whether you developed symptoms or not.  In addition, the test can also determine what kind of antibody you have developed.  The SARS CoV 2 virus has multiple proteins which make up the virus. There is the Spike (S) protein, Nucleocapsid (N), Membrane (M) and Capsule (C).    The Abbott Architect test finds the nucleocapsid (N) antibody and the Ortho-Clinical VITROS test finds the spike (S) antibody.  An antibody against the spike (s) protein would be the best indicator of immunity, but research has to be performed to see if these are ‘neutralizing antibodies’, or antibodies that will prevent infection.  Testing positive for capsule antibodies might infer you are protected, but a direct measurement of the S protein may be needed.  Again, in the SARS outbreak of 2003, only the S protein was shown to be protective/ neutralizing.  Keep in mind, there is a subset of individuals who will not produce antibodies (5-7 %).  

Soon, we will be able to select which type of antibody test you might want.  

When should I get my antibody levels checked after an infection/ suspected infection?

Give your body time to produce the antibodies. Wait at least 3-4 weeks after an exposure.  

There are several groups, including the manufacturer, who recommend checking your antibody levels in as little as two weeks after a suspected infection.  The Cleveland Clinic recently reported that the SARS-CoV-2 virus is different in that it elicits a later antibody response than expected.  Their research noted they saw detectable amounts as late as 3-4 weeks.  Our recommendation is based on this study, which helps prevent a false negative when one did not wait long enough for antibodies to develop  

What is they accuracy rate of the antibody testing performed at Emcura Medical?

Our test is highly accurate with the most often used test at 100% sensitivity and 99.6% specificity. 

Accuracy matters!  We have always selected testing which is accurate and safe.  We were aware that early research showed that fingerstick testing had a false positive rate of up to 60%.   Knowing this, we never offered this type of testing at our clinics!  To date, we have only performed FDA Authorized testing from the start of our COVID 19 testing programs.   The following charts detail accuracy rates for our tests and is taken directly from the CDC website:




In addition, we offer the Vibrant America Test- which finds the status of your IgG, IgM, an IgA antibody against 2 different spike proteins, the nucleocapsid protein, and a membrane protein.   

Vibrant America-     See ‘Markers Measured’ section

Why are you doing antibody testing with a lab draw test instead of a rapid test?

Testing performed though a large lab with a commercial analyzer are usually more accurate than a fingerstick test.  

In the case of COVID 19 testing, the analyzer tests a sample, and it must reach a numerical threshold to be considered positive.  With a finger stick, the operator decides if it is positive based on a visual read of a line, regardless of how faint it is.  This introduces operator error.  Most importantly, the fingerstick tests are TOO UNRELIABLE to rely on.  Our test is approximately 99.6% specific, giving a very low false positive rate. 

Can an antibody test be used to return to work? 

Not at this time.  We would still recommend both an antibody blood draw test and a nasal swab. 

This is not an appropriate use of antibody testing.  Safely returning to work means one individual cannot infect another, and only direct measurement of the virus can be used for this purpose.   A VERY ACCURATE antibody test can also be used to help determine prior exposure and future staffing planning, but we must have official guidelines from the CDC guidance regarding this.  It is possible that more research will prove that those with antibodies to the Spike (S) protein will be immune, and that we may infer immunity to the virus with presence of other antibodies but this must be performed in conjunction with a nasal swab to rule out current infection.   

Can the antibody test prove that you are immune to new COVID 19 infections?

Unfortunately, there is not enough research available to prove this.  

Historical data from the SARS outbreak in 2003 did show that 85% of infected individual did become immune, and new research from Germany and China is showing immunity after recent infection with SARS CoV 2, but we do not have enough information to accurately determine immune status or how long this might last.  An antibody against the spike (S) protein would be the best indicator of immunity, but research has to be performed to see if these are ‘neutralizing antibodies’ (antibodies that will prevent infection).  Testing positive for capsule antibodies might infer you are protected, but a direct measurement of the S protein may be needed.  Again, in the SARS outbreak of 2003, only the S protein antibody was shown to be protective/ neutralizing.  

How do I receive my results? How can I get a copy?

We always call all results, negative or positive!  

We cannot email test results due to HIPAA regulations, but we can send them to a secure fax and we can also print a physical copy for you to pick up.  We would prefer you create a MyQuest account at  Once an account is set up, you can view and print your test results as needed!  

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