SARS-CoV-2 IgG Antibody Test

The SARS-CoV-2 IgG Antibody Test detects IgG antibodies against the coronavirus (SARS-CoV-2), which causes COVID-19. IgG antibodies indicate past infection or vaccination and help assess immune response.

Why is the Test Done?

A doctor may order an SARS-CoV-2 IgG test for:

✅ Checking past COVID-19 infection (even if symptoms were mild or absent)
✅ Assessing immune response after vaccination
✅ Determining exposure in high-risk individuals (healthcare workers, elderly, immunocompromised)
✅ Evaluating potential plasma donors for COVID-19 convalescent plasma therapy

How is the Test Done?

1. Blood Sample Collection:

   • A sample is drawn from a vein.
   • The test is performed using ELISA, CLIA, or rapid immunoassays.

2. Detection of IgG Antibodies:

   • IgG antibodies develop 2-3 weeks after infection or vaccination and can persist for months.

Interpreting the Results

📌 Note:

• A positive IgG test does not mean active infection—it only confirms past exposure or vaccination.
• If an active COVID-19 infection is suspected, an RT-PCR or antigen test is recommended.
• Vaccine-induced IgG may differ from infection-induced IgG, depending on the test used.

Next Steps After a Positive Result

🔬 Additional Tests May Be Ordered:

• SARS-CoV-2 IgM Test: To check for recent infection.
• RT-PCR Test: If symptoms suggest an active infection.
• Neutralizing Antibody Test: To assess protective immunity.

💊 What to Do If Positive?

• If due to past infection, follow-up isn’t usually needed.
• If tested after vaccination, a positive result confirms immune response.
• If immunocompromised, discuss with your doctor about booster doses or further protection measures.