Quick Facts
- Sample: Venous blood draw or fingerstick
- Fasting: Not required
- Turn-around: 5-7 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Know your immune status - Discover if you've developed antibodies from infection or vaccination
- Convenient testing - No doctor visit required, results delivered securely to your portal
- Semi-quantitative results - Get specific numerical values, not just positive/negative
- High accuracy - 98.6-99.9% specificity and 92.7-98.1% sensitivity when properly timed
- Informed decisions - Use results to discuss booster timing with healthcare providers
- Peace of mind - Understand your body's immune response to COVID-19
Who Is This Test For?
- Individuals wanting to check antibodies after COVID-19 vaccination
- People who suspect past COVID-19 infection but were never tested
- Healthcare workers and essential employees at higher exposure risk
- Immunocompromised individuals verifying vaccine response
- Those needing antibody documentation for work or travel
- Anyone interested in monitoring their immune response over time
How It Works – Just 3 Steps
- Order online - No appointment needed, schedule at your convenience
- Visit lab - Quick blood draw at any certified patient service center
- Get results - Secure digital delivery within 5-7 business days
FAQ
When should I order this test? Wait at least 2-3 weeks after vaccination or suspected infection for most reliable results. Testing too early may produce false negatives.
Does a positive result mean I'm protected from COVID-19? The CDC states antibody testing should not determine immunity status, as protective thresholds haven't been established. Results show immune response history.
What's the difference between this and other COVID antibody tests? This semi-quantitative test provides specific numerical values (AU/mL) rather than just positive/negative, allowing detailed antibody level tracking.
Can this test tell me if I need a booster shot? While it shows current antibody levels, the CDC recommends following standard vaccination schedules regardless of antibody results.
How often should I repeat this test? For monitoring purposes, consider repeat testing every 3-6 months to track antibody persistence, especially if immunocompromised.
Will this test detect current COVID-19 infection? No, this test only detects past immune responses. Use PCR or antigen tests for current infection diagnosis.
More Details
What is the purpose of this test?
This test detects and measures IgG antibodies specific to the SARS-CoV-2 spike protein, indicating whether you've developed an immune response from past infection or vaccination (Mayo Clinic 2024). The semi-quantitative approach provides both qualitative (positive/negative) and numerical results, offering more detailed insight than basic antibody tests.
Unlike tests for active infection, this measures your body's adaptive immune response history. It cannot determine current infection status or immunity levels, but provides valuable information about your immune system's encounter with SARS-CoV-2 (CDC 2023).
Who would benefit from this test?
This test serves individuals seeking to understand their COVID-19 immune response without requiring physician visits. It's particularly valuable for those who may have had asymptomatic infections, people assessing vaccine response, or individuals needing antibody documentation (Walk-In Lab 2024).
Healthcare workers, essential employees, and immunocompromised individuals benefit from monitoring their antibody levels over time. The test also helps those making informed decisions about booster vaccinations and personal risk management strategies (LabCorp 2024).
When should I order the SARS-CoV-2 (COVID-19) Antibody (IgG), Spike, Semi-Quantitative Test?
Optimal timing is crucial for accurate results. Wait at least 2-3 weeks after symptom onset, known exposure, or vaccination, as sensitivity reaches 96% after 15 days post-exposure (Quest Diagnostics 2024). Testing within 14 days may result in false negatives due to insufficient antibody development.
If you've had recent fever or COVID-19 symptoms, wait until symptoms resolve and you've been fever-free for 24 hours without medication. Consider testing if you've had resolved symptoms like fever, cough, shortness of breath, or loss of taste/smell from weeks or months ago.
How do I interpret the results?
Results are reported in AU/mL (Arbitrary Units per milliliter) with an upper limit of 800 AU/mL. Higher values generally indicate stronger antibody responses, though specific protective thresholds haven't been established (FDA 2021).
< 0.8 AU/mL (Negative) — No detectable antibodies
- Typical action: Discuss vaccination/booster with provider
0.8–50 AU/mL (Low Positive) — Minimal antibody response
- Typical action: Consider repeat testing in 2–3 weeks
50–800 AU/mL (Positive) — Detectable immune response
- Typical action: Monitor levels over time
> 800 AU/mL (High Positive) — Strong antibody response
- Typical action: Continue routine monitoring
Studies show individuals with detectable spike antibodies had 44% reduced infection risk and 80% reduction in serious outcomes compared to those without antibodies.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
No fasting or special preparation is required for this antibody test (LabCorp 2024). Simply schedule your appointment and arrive at your designated time. Ensure you're well-hydrated and inform the phlebotomist of any medications you're taking.
Avoid testing if you currently have fever or active COVID-19 symptoms, as this may affect result interpretation. If using mobile collection services, be available at your scheduled time and location.
How often should I get tested?
Testing frequency depends on your individual circumstances and risk factors. The following table provides general guidance:
- Healthy individuals post-vaccination: Every 6 months
- Immunocompromised patients: Every 3 months
- Healthcare workers: Every 3–6 months
- Post-infection monitoring: At 3, 6, and 12 months
- Travel documentation needs: As required by destination
Why early detection matters
Understanding your antibody status provides crucial information for personal health management and risk assessment. With global seroprevalence exceeding 97% in many populations, knowing your specific antibody levels helps inform decisions about additional protective measures (HPSC Ireland 2024).
Early detection of waning antibody levels can prompt timely discussions about booster vaccinations, especially important for immunocompromised individuals who may need more frequent monitoring. Regular testing also contributes to public health surveillance efforts tracking population immunity.
Related tests you may consider
Comprehensive Metabolic Panel (CMP-14) Blood Test – Evaluates kidney and liver function, blood sugar, electrolytes, and protein levels to help assess overall metabolic health and detect potential medical conditions.
Complete Blood Count (CBC) with Differential - Assesses overall immune system health and can detect signs of recent infection or inflammation that might affect antibody response.
Lipid Panel Blood Test – Measures total cholesterol, HDL (good cholesterol), LDL (bad cholesterol), and triglycerides to help assess heart health and evaluate the risk of cardiovascular disease.
