COVID-19 Antibody Test
Blood Test Types
IMPORTANT - Test collection is available only to patients who: are asymptomatic; have been asymptomatic for at least 10 days; lack a fever (as assessed by non-contact thermometer checks at time of visit); and are wearing a face mask.
THIS IS NOT A TEST FOR AN ACTIVE INFECTION
Patients suspected of having or confirmed to have active COVID-19 infection or disease may not visit Quest patient service centers, which are not equipped to collect the necessary respiratory specimens for molecular COVID-19 diagnostic testing. Patients who believe they may have COVID-19 are strongly encouraged to contact their healthcare provider.
"This test checks for a type of antibody called immunoglobulin G (IgG) that is the result of past or recent exposure to COVID-19, also known as the novel coronavirus. The human body produces IgG antibodies as part of the immune response to the virus. It usually takes around 10 to 18 days to produce enough antibodies to be detected in the blood.
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. Antibodies typically suggest protective immunity after you’ve recovered or been exposed to COVID-19. However, evidence is still being collected to determine if IgG antibodies provide protective immunity against SARS-CoV-2, the virus that causes COVID-19 infection.
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.
Multiple sources, including the CDC and healthcare experts, recommend you discuss your test results and whether to return to work with your healthcare provider and employer.
PATIENT SERVICE CENTERS - COVID-19 Antibody (IgG) testing requirements.
1. A FACE MASK IS REQUIRED
2. AN APPOINTMENT IS REQUIRED - For the safety of patients and employees, Quest has limited appointment times for COVID-19 Antibody (IgG) testing.
NEW! SARS-CoV-2 Antibody (IgG), Spike, Semi-Quantitative
A SARS-CoV-2 semi-quantitative IgG test result is reported as positive at an index3 of ≥1.00. This positive result indicates that an individual has developed an immune response to a SARS-CoV-2 infection or a SARS-CoV-2 spike vaccine within the limits of the assay.
Conversely, a negative result is reported at an index4 of <1.00. A negative semi- quantitative antibody result means that the patient serum specimen had no SARS-CoV-2 spike IgG antibodies, or that the relative level of antibodies in the patient specimen was below the index cutoff. • Estimated sensitivity of 99.9% based on positive percent agreement (PPA) and specificity of 99.9%, based on negative percent agreement (NPA).
SARS-CoV-2 Antibody (IgG), Spike, Semi-Quantitative - The results of this semi-quantitative test should not be interpreted as an indication or degree of immunity or protection from reinfection. Individuals that have been vaccinated with a SARS-CoV-2 spike or receptor-binding domain vaccine may be positive in this test, and their sero-positivity may or may not be due to a SARS-CoV-2 infection. This test is intended as an aid in identifying individuals with an adaptive immune response to SARS-CoV-2, indicating recent or prior infection. This test may be positive in vaccinated patients. It is unknown for how long antibodies persist following infection and if the presence of antibodies confers protective immunity. This assay should not be used to diagnose acute SARS-CoV-2 infection.
This test may be helpful if you:
- Have had a positive test for COVID-19 and it has been at least 7 days and you want to know if you have detectable levels of IgG antibodies
- Have not experienced a fever or felt feverish in the last 3 days
- Have not experienced new or worsening symptoms of COVID-19 in the past 10 days: loss of smell or taste, shortness of breath or difficulty breathing, feeling weak or lethargic, lightheadedness or dizziness, vomiting or diarrhea, slurred speech, and/or seizures
This test may NOT be helpful if you are:
- Feeling sick or have had a fever within the last 3 full days, please contact a healthcare provider
- Trying to diagnose COVID-19, please contact a healthcare provider
- Less than 7 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
- For the latest information on COVID-19, please visit our website for information for patients.
What will my results tell me? - Your test results may help identify if you were exposed to the virus and, if so, whether or not your body has these antibodies. Although having antibodies usually gives immunity from further infection, there is not enough evidence at this time to suggest that people who have IgG antibodies are protected against future SARS-CoV-2 infections. ?Results from this test also will not provide any information on whether you can spread the virus to others.
If you have questions about returning to work, contact your employer for guidance. Be sure to continue to follow federal, state, and local government guidance regarding social distancing and isolation.
Are there any limitations to IgG antibody tests? - It usually takes around 10 to 18 days after being infected with SARS-CoV-2 for your body to produce enough antibodies for detection in the blood. Getting an IgG antibody test too soon after being infected may cause a negative result that is false (false negative). Additionally, IgG antibody tests may detect IgG antibodies from previous exposure to coronaviruses other than SARS-CoV-2. This can cause a positive result that is false (false positive). There is not enough evidence at this time to suggest that people who have IgG antibodies are protected against future SARS-CoV-2 infections.
Are there any risks involved in getting this test? - There is no risk involved in getting this test. The test is conducted by collecting a blood sample.
How do I prepare for the test? - To have your specimen collected at the patient service center, you will need to wear a face mask, consent to a non-contact thermometer checks at the time of visit, and depending upon the patient service center schedule an appointment. There is no other special preparation other than the requirements to receive this test that is restricted to only to patients who: are asymptomatic; have been asymptomatic for at least 10 days; lack a fever (as assessed by non-contact thermometer checks at time of visit); and are wearing a face mask.
What is coronavirus disease (COVID-19)? Coronavirus disease (also called COVID-19) is a serious respiratory illness. It is caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus), one of the most recently discovered types of coronaviruses. It was first identified in Wuhan, China, at the end of 2019 and has spread globally, becoming a worldwide pandemic. Those who have this disease may or may not experience symptoms, which range from mild to severe.
What is a serology test? This serology? ?test checks for a type of antibody called ?immunoglobulin G (IgG)?. If you’ve been exposed to the SARS-CoV-2 virus, your body produces IgG antibodies as part of the immune response to the virus. This test cannot tell you if you have an active infection with SARS-CoV-2. If you suspect you have COVID-19, follow up with your healthcare provider about getting a molecular (PCR) test.
Note: This test 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, if you test 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.
At this time, antibody testing is mainly used in studies to determine how much of the population has been exposed to COVID-19. There is not enough evidence at this time to suggest that people who have IgG antibodies are protected against future COVID-19 infection. Positive or negative antibody tests do not rule out the possibility of COVID-19 infection. Results also do not provide any information on whether you can spread the virus to others.