SARS-CoV-2 (COVID-19) Antibody, IgG

CPT Code(s):
86769

Turnaround Time:
2 hours

Specimen Requirements

Preferred Specimen:
Serum

Minimum Volume:
1.0 mL

Transport Container:
Serum Separator Tube (SST) or Red Top Tube

Transport Temperature:
Room Temperature

Collection Instructions:
Allow blood to clot completely prior to centrifugation. Separate serum from cells within 45 minutes of collection.

Rejection Criteria:
Citrate or Fluoride plasma specimen; gross hemolysis; lipemia; improper labeling

Stability Criteria

Room Temperature:
8 hours

Refrigerated:
48 hours

Frozen:
30 days

Clinical Significance

The SARS-CoV-2 (COVID-19) Antibody, IgG test is a specific clinical test used to detect the presence of IgG antibodies against the SARS-CoV-2 virus, which is responsible for COVID-19. This test helps in assessing a patient's immune response to a past infection with the virus or to a COVID-19 vaccination.

The clinical significance and diagnostic use of the SARS-CoV-2 Antibody, IgG test include:

1. Past Infection Confirmation: IgG antibodies targeted by this develop several days after the onset of symptoms or following a COVID-19 infection. A positive IgG result indicates that the patient has been previously infected with SARS-CoV-2 and has developed an immune response, even if they were asymptomatic or had mild symptoms. This can help in confirming a past COVID-19 infection, particularly when the patient was not tested for the virus at the time of illness.

2. Immune Response Assessment: The presence of IgG antibodies in the blood suggests that the patient has mounted an immune response against SARS-CoV-2. While the duration and level of antibody protection are still being studied, the presence of IgG antibodies generally indicates some degree of immunity to future infections. However, the level of protection and duration of immunity are still under investigation, and it is important to consider other factors such as the timing of the test, variant strains, and emerging research.

3. Vaccine Response Evaluation: The SARS-CoV-2 Antibody, IgG test is also used to assess the immune response following COVID-19 vaccination. A positive IgG result after vaccination indicates that the patient has developed an immune response to the vaccine and has generated antibodies against the virus. This can provide reassurance about the vaccine's effectiveness and the patient's level of protection against COVID-19.

4. Epidemiological Studies: The SARS-CoV-2 Antibody, IgG test is used in population-level studies to estimate the prevalence of COVID-19 infection within a community or to assess the effectiveness of vaccination campaigns. It provides valuable data on the spread of the virus, the percentage of the population with past infections or vaccination, and the potential level of herd immunity.

It is important to note that the SARS-CoV-2 Antibody, IgG test should not be used as a diagnostic tool for acute COVID-19 infection. It takes time for IgG antibodies to develop, and the test may yield negative results during the early stages of infection. Molecular tests such as PCR are recommended for the diagnosis of active infection.

In summary, the SARS-CoV-2 Antibody, IgG test is an important tool for confirming past COVID-19 infection, evaluating immune response following vaccination, and providing epidemiological insights. It helps assess individual and population-level immunity to SARS-CoV-2 and contributes to the understanding and management of the COVID-19 pandemic.