COVID-19 Antibody Test
Antibodies are proteins that the body produces in response to an infection or vaccine. There are 2 types of COVID-19 antibody tests: a spike protein test and a nucleocapsid test. This blood test is a spike protein test which may detect antibodies from a prior COVID-19 infection or a vaccination, regardless of whether symptoms were present. A nucleocapsid protein test can only detect antibodies from a past infection.
This semiquantitative COVID-19 Antibody Test provides a positive or negative result and a numerical value that can show your immune response over time if you use the same test.
The results of this semiquantitative test should not be interpreted as an indication of degree of immunity or protection from infection.
This test does not require fasting and is only available for persons 18 years of age or older.
This SARS-CoV-2 Antibody (IgG), Spike, Semi-Quantitative test is authorized by the FDA under the Emergency Use Authorization (EUA)* and meets Quest’s high-quality standards.
This COVID-19 Antibody Test may be helpful if you:
- Have previously tested positive for COVID-19 or received a COVID-19 vaccination and want to know if you have detectable levels of IgG antibodies
- Were never diagnosed with COVID-19 and are looking to determine if you may have been previously infected with the virus
You should not get this COVID-19 Antibody Test and instead contact your healthcare provider if you:
- Are feeling sick or have had a fever within the last 72 hours
- Think you are currently infected with COVID-19
- Were diagnosed with COVID-19 in the past 10 days
- Think you may have been exposed to COVID-19 in the past 14 days
This test can sometimes detect antibodies from other related coronaviruses you may have been exposed to, such as a virus that causes the common cold. This can cause a false positive result. Additionally, if you test too soon after infection or vaccination, your body may not have produced enough IgG antibodies to be detected by the test yet, which can lead to a false negative result.
This test may not be helpful if you have a compromised immune system or have a condition that makes it difficult to fight infections. If you are looking for other testing solutions, QuestDirect offers a COVID-19 Active Infection Test, or you can view additional information on Quest Diagnostics COVID-19 testing.
About COVID-19 Antibody Tests
There are 2 ways to develop SARS-CoV-2 (COVID-19) antibodies, either from a natural infection or from vaccination.
After a natural infection, current research shows that it may be best to get antibody testing 3 to 4 weeks after symptom onset or known exposure to COVID-19 to increase the opportunity to detect an immune response.
After vaccination, it is still not known how long it takes to develop antibodies. Based on the latest research, it may be best to wait 3-4 weeks after your vaccination is fully completed. Antibody testing for the purposes of vaccine decision making is not currently recommended by the CDC.
How long antibodies to SARS-CoV-2 remain detectable after infection is not known.
There is not enough evidence to know whether having COVID-19 antibodies indicates that you are immune to reinfection. COVID-19 is highly contagious, and you should continue to practice preventive measures to protect yourself and others, regardless of your antibody level.
Fees and payment
Individuals may have COVID-19 testing fully paid by their health plan or the government. If you are looking for that option, contact your healthcare provider or learn more.
Individuals also have the right to have testing without submitting to insurance or the government for reimbursement. With QuestDirect, you can conveniently purchase this testing online. This option is only for individuals who want to pay directly for the testing and do not plan to seek reimbursement. QuestDirect is unable to provide a receipt that contains the information generally required by health plans for reimbursement. Services purchased through this website are solely your financial responsibility. View COVID-19 Pricing Information.
*About the FDA Emergency Use Authorization (EUA) Status
This test has been authorized by the FDA under an Emergency Use Authorization (EUA). This means that while Quest Diagnostics has validated the test and has the data to believe the test and the collection kit are accurate, this test has not been FDA- cleared or -approved; This test has been authorized by FDA under an EUA for use by authorized laboratories; this test has been authorized only for the detection of IgG Antibodies against SARS-CoV-2, not for any other viruses or pathogens; and, this test is only authorized for the duration of the declaration that circumstances exist justifying the authorization of emergency use on in vitro diagnostics for 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.
Additional studies need to be conducted for this test and others like it to be FDA cleared or approved.
** This test should not be used to diagnose an active COVID-19 infection. If an active infection is suspected, molecular or antigen testing is recommended. Learn more about our QuestDirect COVID-19 Active Infection Test.
Clin Infect Dis. 2020;ciaa760. doi:10.1093/cid/ciaa760
Hanson KE, Caliendo AM, Arias CA, et al