The COVID-19 Antibody Test: What You Should Know About Antibodies and Accuracy 

AdobeStock 443352262 The COVID-19 Antibody Test: What You Should Know About Antibodies and Accuracy 

The body is a remarkable machine with a precise memory for viruses and infections.  This short-term and long-term memory—so to speak—is what protects us and helps us fight off infections throughout our lives. As your children grow, they are exposed to pathogens that they build immunity for. Our cell’s ability to “recognize” viruses has helped in the making of vaccines and treatments throughout history. Antibodies are protein components of the immune system that circulate in the blood, and there’s been a lot of talk about the covid antibody test. 

Here are a couple of things to note on the COVID-19 antibody test. 

A Quick Dive Into the Immune System 

Human beings are highly adaptable and, over time, grow to be quite resilient and resistant to various pathogens. The immune system is composed of the adaptive immune system and the innate immune system. These systems work together to respond to threats and to give your body the necessary arsenal to fight off infections. 

As soon as your child is born, their innate immune system kicks into gear. The adaptive immune system strengthens over time, as children’s bodies are exposed to new antigens and the cells construct antibodies, either naturally or through vaccination. 

The Antibody Army – What Exactly are Antibodies?

An antibody is a type of protein component that forms part of the immune system. These circulate in the blood and have the ability to recognize foreign substances. Antibodies are specialized proteins that are Y-shaped that lock into the antigens. People often compare these antibodies to the “search-and-destroy” battalion that seeks and finds the invader and destroys it with no mercy. This Y-shape is important to the antibody’s function, as the two extending arms will bind to other immune-system compounds. 

The cells of the immune system are made in several organs including: 

  • Adenoids
  • Bone marrow 
  • Lymph nodes
  • Lymphatic vessels 
  • Peyer’s patches 
  • Spleen 
  • Thymus 
  • Tonsils 

The COVID-19 Antibody Test 

The COVID-19 antibody test is a blood test that identifies people who have experienced a previous COVID-19 infection. Antibodies are also called immunoglobulins (Ig).  A detectable level of antibodies can be achieved 1-2 weeks post-infection and after. The test is designed to find this fighting army in the blood and gauge the size and strength of this army. 

What the Antibody Test Might Reveal 

The tests will find antibodies that the body produced during an infection or from vaccination. According to the CDC, some of the antibodies produced against the virus protect against getting infected. People who tested positive for antibodies without ever experiencing any covid symptoms and might reveal that the person might have had an asymptomatic infection. 

Some of the current antibody tests will only detect levels of antibodies from infection and not necessarily from the vaccine. This has caused some confusion among the vaccinated. As NPR reported, however, there are many antibody tests on the market, but while most reveal whether a person has antibodies they may not show the level. Experts say that using the test as the only measuring stick for your immune response can sometimes lead to inaccurate confidence about immunity. 

What is the Accuracy of the COVID-19 Virus Test?

According to Harvard Health, having the antibody test too early is likely to lead to a false result. It’s why it takes about two weeks for the body to produce these antibodies. The number of false negatives is about 20%. Medical experts warn people about antibody tests and receiving false reassurance about immunity from a test with a false-positive result. 

Where Can I Receive an Antibody Test for COVID-19?

Depending on the area where you live, an antibody test for covid is available in a variety of places. Pediatrics on Demand proudly offers antibody testing for COVID-19. Please call in before for COVID-19 screenings. If you’d like to learn more about what we have to offer, reach out to our team! Many CVS locations and other pharmacies also offer testing, as well as national labs like LabQuest—though these might require a request from a physician. 

Emerging Information on Immunity, Antibodies, and Vaccines

According to a study, shows that two months after the second mRNA vaccine (Pfizer/Moderna) the antibody response is lowered by 20% in adults. The study seems to suggest that receiving the full cycle (2 doses) of the Pfizer and Moderna vaccines is critical to get the most antibody protection. The study conducted by Northwestern University also indicates that people that have had a previous SARS-CoV-2 infection are not guaranteed a high enough level of antibodies to fight off another infection. The study also indicated that receiving just one dose of the vaccine might not produce a robust antibody production. 

Should I Get My Child Tested for Antibodies? 

Many parents have wondered about their child’s ability to fight off the virus, especially as the Delta variant has caught the attention of many medical professionals. Only the Pfizer vaccine has been approved for children between the ages of 12-15. Parents with younger children might then worry about their child’s chance of infection or whether their child has had the infection.


As of now, antibody testing for children can be done for parents that wish to find out whether their child has had an infection. If a child plays youth sports or participates in group activities, for example, parents often want to know if a past infection has occurred. 

COVID-19 and Children — Statistics to Note

Although the data seems to suggest that children are not as susceptible to serious symptomatic infection, they can carry and transmit the virus. Vaccination among adults is then a good way to continue to slow the spread. Recent data from the American Association of Pediatrics reports that among states reporting, children made up about 1.6%-3.6% of total hospitalizations. 

A comprehensive study in 2020, found that children could carry a viral load even with asymptomatic infection. Generally, the concern with children is that they may carry the disease and spread it to more vulnerable members. A report in August of 2021, stated that while cases in children have steadily increased, hospitalizations and serious infections remain rare. Children made up less than .25% of deaths and based on reports as late as July 29, a total of 358 children have died from covid since the beginning of the pandemic. 

Want to Know More About Testing for Your Child? Come By Peds on Demand

We know that information about vaccines, infections, and antibody tests can be confusing and overwhelming. It’s also true that information and recommendations are often changing and consistently being updated. The medical community is still learning about the virus and watching out for new variants. 

Need quality child healthcare? Have questions about covid and your child’s health? Call our pediatricians today and come by the office!