Antibody Testing for COVID-19 FAQs

The COVID-19 antibody test is a blood test that measures SARS-CoV-2 specific IgG antibody levels as the result of past or recent exposure to COVID-19, also known as coronavirus. This is not a test for an active infection. Based on early evidence, IgG is expected to be elevated in the majority of patients by 14 days after the onset of symptoms. The timeline for IgG elevation in asymptomatic patients is still being studied.

For most viral illnesses, a positive antibody means prior exposure to a virus and some degree of immunity to future infection. COVID-19 is a novel (new) infection, so it is unclear if a positive antibody definitively offers immunity. 

This test does not require fasting and is only available for those 18 years of age or older.

Antibody tests play a critical role in the fight against COVID-19 by assessing the levels of immune response in populations and individuals. Antibody blood testing can help healthcare professionals and public authorities make decisions about people returning to work, and easing social distancing and shelter-in-place measures. 

Individually, test results may help identify if you were previously exposed to the virus and, if exposed, can check whether or not your body has produced antibodies. Currently, the FDA supports antibody testing with the following important points:

• Antibody tests can play a critical role in the fight against COVID-19
• Testing can help identify who may have been exposed to SARS-CoV-2, the virus that causes the COVID-19 infection, and potentially developed an immune response
• Right now, it is unclear whether these individuals may be less susceptible to infection, but in the future, broad use of antibody tests and clinical follow-up will provide more information on this point

The CDC and healthcare experts recommend discussing your test results and whether to return to work with your healthcare provider and employer.

• If you were never diagnosed with COVID-19, this test can help determine if you may have been previously exposed to the virus.
• If you were diagnosed with COVID-19, this test can check whether or not your body has produced antibodies.

As stated by the FDA, results from antibody testing should not be used as the sole basis to diagnose or exclude SARS-CoV-2 infection or to inform infection status. Negative results do not rule out acute SARS-CoV-2 infection. Positive results may be due to past or present infection with non-SARS-CoV-2 coronavirus strains.  

This serology test has a specificity greater than 99.8% and sensitivity of 100%. High specificity is crucial to determine reliably if a person has been exposed to the virus and if the patient has developed antibodies. This is much more accurate than most rapid finger prick tests available.

COVID-19 Antibody Test is recommended:

• If you previously had COVID-19 symptoms (Fever, persistent cough, shortness of breath, body aches) and have recovered after 14 days. 
• If you received a positive test result for COVID-19 and have recovered after 14 days.
•  If you believe you have come in contact with someone who had the COVID-19 virus and have quarantined for 14 days.

The CDC stated that “Clinicians should use their judgment to determine if a patient has signs and symptoms compatible with COVID-19 and whether the patient should be tested”.

COVID-19 Antibody Test is NOT recommended if you are:

• Feeling sick or have had a fever within the last 14 full days
• Trying to diagnose COVID-19
• Less than 14 days since being tested for and diagnosed with COVID-19
• Directly exposed to COVID-19 in the past 14 days
• A person with a compromised immune system, a condition that makes it difficult to fight infections
• In need of a sign off for blood donation

If any of these are true, please contact a primary or emergency healthcare provider.

Antibody testing is not intended for use in individuals with an active COVID-19 infection, including individuals with symptoms. Patients suspected of having or confirmed to have active COVID-19 infection or disease may not visit JECT locations, which are not equipped to collect the necessary respiratory specimens for molecular COVID-19 diagnostic testing. Clients who believe they may have COVID-19 are strongly encouraged to contact their healthcare provider.

We are offering appointments weekly. Schedules, availability and online booking are available at jectnyc.com.

No referral required.

Clients will have their results in 1-3 days. For information on how to understand your COVID-19 test results, please refer to your results email.

Regardless of your results, you should continue to exercise universal precautions such as social distancing, quarantining, frequent hand washing, wearing of a mask or face cloth in public, and other CDC guideline recommendations. COVID-19 is a new infection, and it is unclear if a positive antibody definitively offers immunity.

Note: Tests can sometimes detect antibodies from other coronaviruses, which can cause a false positive result if you have been previously diagnosed with or exposed to other types of coronaviruses. Additionally, tested too soon, your body may not have produced enough IgG antibodies to be detected by the test yet, which can lead to a false negative result.

We take this situation very seriously and that means we have the following protocols in place:

• All clients will be required to fill out a questionnaire prior to their appointment pertaining to health status and potential exposures. The questionnaire will be texted to you via our secure, HIPAA compliant texting platform. 
• Clients will be asked to use hand sanitizer and will receive a temperature-reading upon admission to JECT. Hand sanitizer is available for use at the front desk and in every treatment room. 
• Our team will be wearing PPE for both your protection and ours. 
• Clients will be required to wear a mask as well. If you do not have one, you will be given one before entering. 
• An antimicrobial barrier protection has been applied to all surfaces.* Every surface clients come in contact with is sanitized immediately after each appointment as well.
• Availability has been reduced to take appropriate social distancing precautions.

We ask that clients be responsible and communicative. If there is any change in your health status following your appointment, including diagnosis with Coronavirus and/or quarantine, please immediately notify us at info@jectnyc.com.

*ClearCabin Barrier is an antimicrobial barrier treatment that when applied to a surface forms an invisible bio-barrier coating that wages non-toxic warfare against microbes, including bacterial and viral contaminants. Typical disinfectants kill viruses and bacteria, but once the product dries, there’s no further protection. ClearCabin Barrier protects surfaces for up to 90 days.

The serology antibody tests run by JECT were released for use under the FDA guidance, "Policy for Diagnostic Tests for Coronavirus Disease-2019 during the Public Health Emergency," updated March 16, 2020, and has been registered with the FDA, but not reviewed. It is provided pursuant to the US Food and Drug Administration (FDA) guidance that immunoassays for COVID-19 are less complex than molecular assays, and therefore notification is sufficient to be performed by a high complexity laboratory.  Pertinent information for COVID-19 antibody tests that have not been FDA reviewed:

• This test has not been reviewed by the FDA.
• Negative results do not rule out SARS-CoV-2 infection, particularly in those who have been in contact with the virus. Follow-up testing with a molecular diagnostic should be considered to rule out infection in these individuals.
• Results from antibody testing should not be used as the sole basis to diagnose or exclude SARS-CoV-2 infection or to inform infection status.
• 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.

Positive: You produced the COVID-19 IgG antibody and have a high likelihood of prior infection. Some patients with past infections may not have experienced any symptoms. It is unclear at this time if a positive IgG infers immunity against future COVID-19 infection. Please continue with universal precautions: social distancing, hand washing and when applicable PPE such as masks or gloves.

Negative: You tested negative for COVID-19 IgG antibody. This means you have likely not been infected with COVID-19. Please note, it may take 14-21 days to produce detectable levels of IgG following infection. If you had symptoms consistent with COVID-19 within the past 3 weeks and tested negative, repeat testing in 1-2 weeks may yield a positive result.

Equivocal: Your test results could not be interpreted as Positive or Negative. The most common reasons for equivocal results are presence of an immune response but unclear if against the infection being tested for (COVID-19 in this case) or similar infections (the common cold is a type of coronavirus). If indicated, a repeat test may yield more reliable results.

“If you have fully recovered from COVID-19, you may be able to help patients currently fighting the infection by donating your plasma. Because you fought the infection, your plasma now contains COVID-19 antibodies. These antibodies provided one way for your immune system to fight the virus when you were sick, so your plasma may be able to be used to help others fight off the disease.” – The FDA

In coordination with the U.S. Food and Drug Administration (FDA), the Red Cross and other local organizations, such as New York-Presbyterian, Mount Sinai, and Columbia University Irving Medical Center are seeking people who are fully recovered from COVID-19 to sign up to donate plasma as treatment for patients with serious or life-threatening infections. Learn more and find sites near you collecting plasma donations here:

U.S. Food and Drug Administration (FDA)

The Red Cross

The New York Blood Center

Columbia University Irving Medical Center

Mount Sinai

New York Presbyterian

NY Department of Health

Coronavirus Hotline: 1-888-364-3065 

  Centers for Disease Control and Prevention

Coronavirus.gov