The SARS-CoV-2 Semi-Quantitative IgG Antibody test is a blood test that measures the level of IgG antibodies your body has produced in response to the SARS-CoV-2 virus, the virus responsible for COVID-19. Unlike a qualitative test that gives a simple “positive” or “negative” result, this semi-quantitative test estimates the amount of antibody present and provides a numerical value — giving more detailed insight into your immune system’s response.
Immunoglobulin G (IgG) antibodies are part of your body’s long-term immune defense system. After a person is exposed to a virus like SARS-CoV-2 — either through natural infection or vaccination — the immune system produces IgG antibodies to help fight off future infections. These antibodies typically appear within 1 to 3 weeks after infection or immunization and may remain in the blood for months or longer, although levels naturally decline over time.
The SARS-CoV-2 Semi-Quant IgG Ab test is often used to:
Determine if you've had a past COVID-19 infection, especially if you were asymptomatic or not tested at the time.
Check for an immune response after vaccination, especially in people who are immunocompromised or at high risk.
Track antibody levels over time, often as part of clinical studies or public health surveillance.
Provide supporting evidence when evaluating suspected long COVID or post-viral complications.
It is not used to diagnose an active COVID-19 infection. For that, you would need a PCR or antigen test.
If your test shows detectable levels of SARS-CoV-2 IgG antibodies, it means your immune system has responded to the virus or vaccine. This result may indicate:
A previous infection with SARS-CoV-2, even if you didn’t have symptoms.
A successful immune response to a COVID-19 vaccine.
Possible short-term immunity, though protection can vary by individual and over time.
Your test may include a numerical value or index — higher numbers generally mean more antibodies, but there is no universally accepted "protective level" at this time.
A negative or very low IgG antibody level suggests:
No prior exposure to the virus or vaccine.
The test was done too early, before your body had time to produce IgG antibodies.
Antibody levels have waned over time, which is common and doesn’t necessarily mean you’re no longer protected.
You may not have mounted a strong immune response due to immune suppression or chronic illness.
Antibody presence does not guarantee immunity. It’s one part of a complex immune system that also includes T-cells and memory B cells.
The type of antibodies measured matters — some tests detect antibodies to the spike (S) protein (used in most vaccines), while others detect antibodies to the nucleocapsid (N) protein (which typically indicates natural infection).
The semi-quantitative format provides a relative measure, not an exact titer. It's useful for tracking trends, not confirming full immunity.
Most people don’t need follow-up unless:
You’re immunocompromised and your doctor is monitoring your response to the vaccine.
You're being evaluated for long COVID symptoms.
You’re part of a study or work in a high-risk setting like healthcare.
Your healthcare provider may recommend additional testing or booster shots depending on your results and risk factors.
The SARS-CoV-2 Semi-Quant IgG Ab test gives a detailed look at your immune system's history with COVID-19. A positive result typically means you’ve developed antibodies through infection or vaccination, while a negative result suggests no prior exposure or a diminished immune response. While it can offer insight into your immune status, this test is not a direct measure of immunity and should always be interpreted with your clinical history and vaccination status in mind.
Your medical lab tests hold vital information about your health. Our tools help you understand what's going on and how to take action.
Cancel or upgrade anytime
Anthony
Unlimited Plan Member since 2021
I have been using Healthmatters.io since 2021. I travel all over the world and use different doctors and health facilities. This site has allowed me to consolidate all my various test results over 14 years in one place. And every doctor that I show this to has been impressed. Because with any health professional I talk to, I can pull up historical results in seconds. It is invaluable. Even going back to the same doctor, they usually do not have the historical results from their facility in a graph format. That has been very helpful.
Karin
Advanced Plan Member since 2020
What fantastic service and great, easy-to-follow layouts! I love your website; it makes it so helpful to see patterns in my health data. It's truly a pleasure to use. I only wish the NHS was as organized and quick as Healthmatters.io. You've set a new standard for health tracking!
Paul
Healthmatters Pro Member since 2024
As a PRO member and medical practitioner, Healthmatters.io has been an invaluable tool for tracking my clients' data. The layout is intuitive, making it easy to monitor trends and spot patterns over time. The ability to customize reports and charts helps me present information clearly to my clients, improving communication and outcomes. It's streamlined my workflow, saving me time and providing insights at a glance. Highly recommended for any practitioner looking for a comprehensive and user-friendly solution to track patient labs!
Guiding our users for 10 years to promptly understand, track, and act on their laboratory results.
$15/month
Cancel your subscription at any time.
$250/once
full premium version
$45/month
track your clients’ labs
Cancel your subscription at any time.
Guiding our users for 10 years to promptly understand, track, and act on their laboratory results.
Personal plans
track personal results
Professional Plan
track multiple client's results
$15/month
$250/once
own it for life
$45/month
for health professionals
Complete Plan
Unlimited Plan
$15 / month
$250 full version
Are you a health professional?
Level up your lab report analysis with our Pro plan, built for health practitioners like you.
Health Business Account
$45/month
Cancel your subscription at any time.
Unlock additional Pro plans when you sign up.
Anthony
Unlimited Plan Member since 2021
I have been using Healthmatters.io since 2021. I travel all over the world and use different doctors and health facilities. This site has allowed me to consolidate all my various test results over 14 years in one place. And every doctor that I show this to has been impressed. Because with any health professional I talk to, I can pull up historical results in seconds. It is invaluable. Even going back to the same doctor, they usually do not have the historical results from their facility in a graph format. That has been very helpful.
Karin
Advanced Plan Member since 2020
What fantastic service and great, easy-to-follow layouts! I love your website; it makes it so helpful to see patterns in my health data. It's truly a pleasure to use. I only wish the NHS was as organized and quick as Healthmatters.io. You've set a new standard for health tracking!
Paul
Healthmatters Pro Member since 2024
As a PRO member and medical practitioner, Healthmatters.io has been an invaluable tool for tracking my clients' data. The layout is intuitive, making it easy to monitor trends and spot patterns over time. The ability to customize reports and charts helps me present information clearly to my clients, improving communication and outcomes. It's streamlined my workflow, saving me time and providing insights at a glance. Highly recommended for any practitioner looking for a comprehensive and user-friendly solution to track patient labs!
Healthmatters is a highly-personalized health dashboard.
Instead of searching for your lab results in different places or tracking them down from different providers, Healthmatters houses, organizes, and interprets them all in one central location.
With a Healthmatters account, you can dive into the details of each biomarker and gain insights into the meaning behind your medical test data, anytime, anywhere.
For our professional users, Healthmatters provides intuitive tools that not only streamline analysis but also save valuable time when delving into your client's lab report history.
Healthmatters.io personal account provides in-depth research on 4000+ biomarkers, including information and suggestions for test panels such as, but not limited to:
You can combine all test reports inside your Healthmatters account and keep them in one place. It gives you an excellent overview of all your health data. Once you retest, you can add new results and compare them.
If you are still determining whether Healthmatters support your lab results, the rule is that if you can test it, you can upload it to Healthmatters.
While we work with many popular labs, we welcome reports from lots of other places too.
It's as simple as this: if you can get a test done, you can upload it to Healthmatters and we can interpret results from any lab out there. If laboratories can analyze it, we can interpret it.
If you’re on the hunt for a specific biomarker, contact us and we'll add it to our database. Anything from blood, urine, saliva, or stool can be uploaded, understood, and tracked with your Healthmatters account.
There are two ways to add your test reports to your Healthmatters account. One option is to input the data using the data entry forms. The other method is to utilize our "Data entry service."
Our data entry forms offer an easy, fast, and free way for you to input the reports yourself. Self-entry allows you to add an unlimited number of reports at no cost. We make the self-entry process user-friendly, providing dozens of templates that pre-populate the most popular laboratory panels and offering instant feedback on entered values.
For those who prefer assistance, we offer a "Data entry service" to help you input your data. Simply attach an image or file of your lab test results, and a qualified team member from our data entry team will add the results for you.
We support various file types, including PDFs, JPGs, or Excel. This service is particularly useful if you have many reports to upload or if you're too busy to handle the data entry yourself.
Our special data entry service makes it easy to add your results to your private dashboard. Just attach an image or a file of your lab test results, and our skilled data entry team will do the work for you. It's all done by humans, ensuring that your data is entered accurately and with personal care for each client.
Depending on your account, the data entry service can be included for free or come at an additional cost of $15 per report.
For users on the Complete monthly plan, the first report is entered free of charge, and each additional report incurs a fee of $15.
Unlimited account holders enjoy the entry of ten reports without charge. Subsequent reports are subject to a $15 fee per report.
Additionally, users on the Complete plan can upgrade to a yearly subscription from the account settings. The annual subscription includes a data entry service for five reports.
The Unlimited plan is a one-time purchase for $250, and it covers your account for a lifetime with no additional payments.
For the Complete plan, the cost is $15 per month. You have the flexibility to cancel it anytime through your account settings, ensuring no further payments. To avoid charges, remember to cancel at least a day before the renewal date. Once canceled, the subscription remains active until the end of the current billing cycle.
Additionally, you can upgrade to the yearly Advanced plan from within your account. The annual cost is $79, and it comes with a data entry service for five reports.
You can always upgrade to a lifetime version with a prorated price from a monthly or yearly subscription.
Simply log in and navigate to your account settings to cancel your subscription. Scroll down to locate the 'Cancel' button at the bottom of the page. Ensure you cancel at least one day before the renewal date to prevent any charges. Once cancellation is requested, the subscription remains active until the conclusion of the current billing cycle.
Our goal has been to make your Healthmatters account as intuitive as possible.
We’ve crafted multiple ways for you to navigate your data, whether you're glancing at a single report or delving into your historical test reports.
1. Graph View:Dive into a visual journey with our biomarker graphs, showcasing over 40 data points. Combining years of results unveils trends, empowering you to make informed decisions. Our visualization tools make it a breeze to compare and understand changes over time, even if your results are from different labs. A search function and filters simplify the exploration of extensive data, allowing you to focus on what needs attention.
2. All Tests ViewExplore neatly organized reports on a timeline, highlighting crucial details like dates, critical results, and lab/panel names. Each report opens up to reveal in-depth descriptions and additional recommendations for each biomarker. The history of previous results is just a click away, and you can download a comprehensive report for deeper insights. Color-coded and user-friendly, it's designed for easy reading, understanding, and navigation.
3. Table View:For a holistic view of all biomarkers side by side, our table view is your go-to. Results are neatly displayed in a categorized and dated table, ideal for those with an extensive test history. Utilize sorting, filters, and color-coding to enhance your analysis and gain extra insights.
Yes, you can download information from your account. We can compile your labs into a CSV file. To download all your labs, you can go to Account Settings, and at the bottom of the page, you will find a link to download your information.
Yes, you can print your report. To do so, navigate to "All tests" and open the report you wish to print. You'll find a print button in the right corner of the report. Click on it, and your browser's print window will open. If you prefer to print in a bigger typeface, adjust the scale using the print window settings.
Yes, you can! We highly recommend activating Two-Factor Authentication (2FA) for your account. To do so, please navigate to the "Profile and Security" section of your account, where you will find instructions for activating 2FA.
Yes, you can. When entering values for the biomarker, you will see an "Edit Range" button. Click this button, and you'll have the option to enter a custom range.
A personal account is all about keeping your own lab test results in check. It's just for you and your personal use.
The professional account is designed for health professionals who wish to track and organize their clients' laboratory results.
To learn more about Healthmatters Pro, please refer to the professional page.
At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.
14.3.3 ETA PROTEIN, 21-Hydroxylase Antibody, Acetylcholine Receptor (AChR) Antibody, Activated partial thromboplastin time (APTT), Alpha 2-Macroglobulins, Qn, Alpha Melanocyte Stimulating Hormone, ANA SCREEN A, ANA SCREEN B, ANA SCREEN, IFA, ANA Screen, IFA (Positive, Negative), ANA titer, Anti-C1Q Ab, IgG (RDL), Anti-DBL-Strand DNA Ab, Anti-dsDNA (Double-stranded) Ab by Farr method (RDL), Anti-dsDNA ab (Farr Assay), Anti-IgE, ANTI-RNP (CU), Anti-Smith Antibody, Anticardiolipin Ab,IgA,Qn, Anticardiolipin Ab,IgG,Qn, Anticardiolipin Ab,IgM,Qn, Antinuclear Ab, HEp-2 Substrate, S, Antinuclear Antibodies (ANA) Screen, Reflex ANA IFA dsDNA Antibodies, Antinuclear Antibodies Direct (ANA Direct), Antiphosphatidylserine IgA, Antiphosphatidylserine IgG, Antiphosphatidylserine IgM, Antithrombin Activity (ATIII), Antithrombin III activity, Baski sleepy, Beta Strep Gp A Culture, Bordetella Pertussis Toxin (PT) IgG Antibody (IA), C1 Esterase Inh. Ag (Antigen), C1 Esterase Inhibitor, Func, C1 Esterase Inhibitor, Serum, C1q Binding Assay, C3A Desarg Fragment, C4a Level by RIA, CARDIOLIPIN AB (IGA), CARDIOLIPIN AB (IGG), CARDIOLIPIN AB (IGM), Carnitine Esters, CARNITINE, ESTERS, Carnitine, Free, Carnitine, Total, CCP Antibodies IgG/IgA, Centromere, Chromatin, Coccidioides Ab by CF, Coccidioides Ab, IgG, EIA, Coccidioides Ab, IgM, EIA, Complement C1q, Quantitative, Complement C3, Complement C3a, Complement C4, Serum, Complement C4a, Complement Component C1Q, Complement, Total (CH50), Complement, Total (CH50), Quest Diagnostics, Cyclic Citrullinated Peptide Antibody, Cysticercosis (Taenia solium), Dilute Russell's viper venom time (dRVVT), Diphtheria Antitoxoid Antibody, DNA AB Double Stranded Titer, DNA Double-Stranded Ab, IgG, dRVVT Confirm, DRVVT SCREEN, dRVVT Screen Ratio, ds-DNA Antibody, IgG, dsDNA, ECP, ENA Screen, ENA to Smith (Sm) Antibody, ENA-6 Reflexed, Eosinophil Cationic Protein (ECP), Epidermal Growth Factor (EGF), Erythrocyte Sedimentation Rate (ESR), Esterified/Free Ratio, F004-IgE Wheat, Free Kappa Lt Chains, Serum, Fusarium Proliferatum/Moniliforme IgG, Gammaglobulin A, Gammaglobulin G, Gammaglobulin M, Ganglioside Antibodies - GM1 (IgG), Ganglioside Antibodies - GM1 (IgM), Ganglioside Antibodies - GQ1b (IgG), Gastrin, GlycA, Haemophilus Influenzae Type B Antibody (IgG), Helicobacter pylori Abs, Serum, Hemoglobin A2 (Quant), Hexagonal Phase Phospholipid, HISTAMINE RELEASE (CHRONIC URTICARIA), Histamine, Plasma, Histamine, Whole Blood, Histone, HLA-B27 (Human Leukocyte Antigen B27), Human Transforming Growth Factor Beta 1 (TGF-b1), IGE ANTIBODY (ANTI IGE IGG), Immunofixation Result, Serum, Immunoglobulin A, Qn, Serum, Immunoglobulin D, Quant, Serum, Immunoglobulin E, Immunoglobulin E, Total, Immunoglobulin G, Qn, Serum, Immunoglobulin M, Qn, Serum, INFg, Influenza Type A Antibody Serum, Influenza Type B Antibody Serum, Interleukin-2, Serum, Interleukin-6, Jo 1 Antibodies, IgG, Serum, JO-1, Kappa/Lambda Ratio, Serum, Liver Kidney Mic IgG, Liver-Kidney Microsomal Antibodies, Lupus Anticoagulant, Lysozyme, Serum, Mannose Binding Lectin (MBL), Measles Antibodies, IgG, Monocyte Chemotactic Protein-1 (MCP-1), Mumps Abs, IgG, PEP A2Glob, PHOSPHATIDYLETHANOLAMINE AB (IGA), PHOSPHATIDYLETHANOLAMINE AB (IGG), PHOSPHATIDYLETHANOLAMINE AB (IGM), PHOSPHATIDYLSERINE AB (IGA), PHOSPHATIDYLSERINE AB (IGG), PHOSPHATIDYLSERINE AB (IGM), Plasminogen Activator Inhibitor (PAI-1) AG, Procalcitonin, Proliferating Cell Nuclear Antigen (PCNA), Prothrombin Fragment 1.2, Prothrombin Time (PT), Prothrombin Time (PT) INR, QUANTIFERON® -TB GOLD PLUS, 1 TUBE, RA Latex Turbid, RATIO (CBA/VW AG), Reptilase Clotting Time, Reptilase Time, RF, IgA by EIA (RDL), RF, IgG by EIA (RDL), RF, IgM by EIA (RDL), Rheumatoid factor (RF), Rheumatoid Factor IgA, Rheumatoid Factor IgG, Rheumatoid Factor IgM, Ristocetin Cofactor, RNA Polymerase III Antibodies, RNP/Sm, Ro-52kD Antibody, Rubella Antibodies, IgG, SARS-CoV-2 Semi-Quant IgG Ab, SARS-CoV-2 Spike Ab Interp, Schistosoma IgG, Scl-70, Sed Rate by Modified Westergren, Semi-Quant RF, SICKLE CELL SCRN, Sirolimus, Whole Blood, Sm, SM/RNP Antibody, Smith/RNP (ENA) Ab, IGG, Smooth Muscle Abs, IFA, Ss-B/La Ab Igg, SSA, SSA-52 (Ro52) (ENA) Antibody, IgG, SSA-60 (Ro60) (ENA) Antibody, IgG, SSB, ssDNA, Tacrolimus, Highly Sensitive, LC/MS/MS, Tacrolimus, Whole Blood, TB1-NIL, TB2-NIL, Tetanus Antitoxoid IgG Ab, TGF-b1, Thrombin time, Thrombin-Antithrombin TAT, TNFb, Trans. Growth Fact. beta 1, Transforming Growth Factor beta, Plasma, Tryptase, Tumor Necrosis Factor, Varicella Zoster IgG, Varicella-Zoster Virus (VZV) DNA, Qualitative, Real-Time PCR, VEGF, Plasma, VEGF, Serum, von Willebrand Factor Activity, Von Willebrand Factor Antigen (vWF), VW Activity/VW Antigen Ratio, VWF: COLLAGEN BINDING
