COVID-19 IgG Testing - SARS-CoV-2 (COVID-19) (IgG)

The COVID-19 IgG Testing - SARS-CoV-2 (COVID-19) (IgG) test contains 1 test with 1 biomarker.

NEW - SARS-CoV-2 Antibody (IgG), Spike, Semi-Quantitative

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).

Clinical Significance

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.

Most Common Questions About the SARS-CoV 2 COVID-19 IgG Antibody test:

Understanding the SARS-CoV-2 COVID-19 IgG Antibody Test

What is the SARS-CoV-2 COVID-19 IgG Antibody test?

The SARS-CoV-2 COVID-19 IgG Antibody test is a blood test that checks for the presence of IgG antibodies against the SARS-CoV-2 virus, the virus that causes COVID-19. These antibodies typically indicate a past infection and a degree of immune response.

Why is the SARS-CoV-2 COVID-19 IgG Antibody test performed?

This test is performed to determine if an individual has had a past infection with SARS-CoV-2, even if they did not have noticeable symptoms. It is also used to identify individuals who may have developed an immune response, for example, after vaccination.

Interpreting SARS-CoV-2 COVID-19 IgG Antibody Test Results

What do positive SARS-CoV-2 COVID-19 IgG Antibody test results mean?

A positive result indicates the presence of IgG antibodies against the SARS-CoV-2 virus. This usually means that the person has been infected with the virus in the past or has responded to a COVID-19 vaccine.

What do negative SARS-CoV-2 COVID-19 IgG Antibody test results mean?

A negative result suggests that the person hasn't been infected with SARS-CoV-2, or their immune system hasn't developed detectable antibodies, possibly because the test was done too soon after infection or vaccination.

Can I still get COVID-19 if my SARS-CoV-2 COVID-19 IgG Antibody test is positive?

Yes, a positive test doesn't guarantee immunity. It merely indicates that you've had a past infection or have responded to a vaccine. The level of immunity and its duration varies between individuals.

SARS-CoV-2 COVID-19 IgG Antibody Test and COVID-19 Vaccination

How can the SARS-CoV-2 COVID-19 IgG Antibody test determine if I've responded to a COVID-19 vaccine?

After vaccination, your immune system should produce antibodies against the virus, including IgG antibodies. The presence of these antibodies indicates a response to the vaccine.

If I have high antibody levels after the SARS-CoV-2 COVID-19 IgG Antibody test, does that mean I have a strong immunity to COVID-19?

While a positive result shows that your immune system has responded to the virus or a vaccine, it doesn't necessarily correlate with the level of immunity or protection you have against reinfection. Further research is required to understand this correlation fully.

If I don't have detectable antibodies after receiving a COVID-19 vaccine, does that mean the vaccine didn't work?

Not necessarily. The COVID-19 vaccines primarily stimulate another part of the immune system—T cells—which the SARS-CoV-2 COVID-19 IgG Antibody test does not measure. Some vaccinated individuals may not develop detectable antibody levels but still have immune protection.

SARS-CoV-2 COVID-19 IgG Antibody Test and Other Conditions

Can the SARS-CoV-2 COVID-19 IgG Antibody test differentiate between antibodies from a vaccine and those from a natural infection?

No, the test cannot differentiate between antibodies produced in response to a natural infection and those produced after vaccination. However, certain tests can identify antibodies to specific viral proteins that only appear after infection and not vaccination.

Are there conditions that can affect the SARS-CoV-2 COVID-19 IgG Antibody test results?

Yes, conditions that affect the immune system, such as immunodeficiency disorders or treatments like chemotherapy, may affect the results.

SARS-CoV-2 COVID-19 IgG Antibody Test and Other Tests

How does the SARS-CoV-2 COVID-19 IgG Antibody test compare to a COVID-19 PCR test?

The PCR test is used to diagnose an active infection by detecting viral RNA, while the SARS-CoV-2 COVID-19 IgG Antibody test looks for antibodies to the virus, indicating a past infection or immune response.

How does the SARS-CoV-2 COVID-19 IgG Antibody test relate to the COVID-19 antigen test?

The antigen test, like the PCR test, is used to diagnose active infections by detecting viral proteins. The antibody test, on the other hand, looks for an immune response to a past infection or a vaccine.

Can the SARS-CoV-2 COVID-19 IgG Antibody test replace the need for a COVID-19 vaccine?

No, the presence of antibodies doesn't necessarily mean you're immune to COVID-19. Vaccination is still the best way to protect against severe disease.

Future of SARS-CoV-2 COVID-19 IgG Antibody Testing

How might the use of the SARS-CoV-2 COVID-19 IgG Antibody test evolve with our growing understanding of COVID-19 immunity?

As we learn more about immunity to COVID-19, this test might be used to help assess the strength and duration of immunity after infection or vaccination.

Could the SARS-CoV-2 COVID-19 IgG Antibody test be used to determine the need for a booster vaccine?

Potentially, but further research is needed. A low antibody level could potentially indicate a need for a booster, but other factors like T cell immunity also play a role.

Could the SARS-CoV-2 COVID-19 IgG Antibody test be used to predict susceptibility to variants of the SARS-CoV-2 virus?

This is still under investigation. Current evidence suggests that antibodies may offer some protection against variants, but the level of protection might vary.

Could the SARS-CoV-2 COVID-19 IgG Antibody test be used to monitor the effectiveness of new COVID-19 treatments?

Potentially, it could be used as a part of a comprehensive assessment of how well new treatments stimulate an immune response.

Can the SARS-CoV-2 COVID-19 IgG Antibody test help in managing long-term effects of COVID-19?

Yes, in some cases, the test might help identify individuals who have had a past infection and are experiencing lingering symptoms, known as 'long COVID.'

Could the SARS-CoV-2 COVID-19 IgG Antibody test be part of a pandemic preparedness strategy in the future?

Yes, the test could be used to track infection rates in a population and to identify individuals who have had the infection and may have some level of immunity.

Could there be new uses for the SARS-CoV-2 COVID-19 IgG Antibody test in managing public health?

Yes, for example, it could be used in seroprevalence studies to estimate the percentage of a population that has been infected with SARS-CoV-2.

How could advances in testing technology influence the future of the SARS-CoV-2 COVID-19 IgG Antibody test?

Improvements in technology could lead to more accurate and faster tests, potentially even point-of-care or at-home antibody testing.

How might the SARS-CoV-2 COVID-19 IgG Antibody test be used in the study of COVID-19 reinfections?

By identifying individuals who have been infected before, researchers can monitor these individuals for potential reinfection, contributing to our understanding of COVID-19 immunity.

Can the SARS-CoV-2 COVID-19 IgG Antibody test be used to determine if someone is contagious?

No, the antibody test doesn't indicate whether a person is currently infectious. It only suggests past infection or an immune response to a vaccine.

Is the SARS-CoV-2 COVID-19 IgG Antibody test used to diagnose an active COVID-19 infection?

No, the antibody test doesn't diagnose an active infection. It's used to identify past infection or response to a vaccine. An active infection is diagnosed with tests that detect viral RNA or proteins.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.