The COVID-19 antibody test identifies y-shaped proteins that target invading molecules when someone is infected with coronavirus, effectively neutralizing them. So when these antibodies are present in our system, they indicate that, at some point, we likely were infected with the virus. They indicate that our body’s immune system was able to fight off the infection.
But why is it important to know if someone was previously infected if they have since fought off the virus? Antibody tests—or serological tests—received a lot of attention early in the pandemic because many associated it with immunity. But are those with antibodies present in their system immune to the virus? Let’s learn more.
We know that antibodies are detectable and traced in the blood several days after a patient has displayed symptoms as a result of COVID-19 infection. Traces of antibodies are like the proverbial trail of breadcrumbs indicating our body is responding to infection. But because it takes several days before antibodies are detectable, serological tests are not useful for detecting infection in the same way antigen or molecular COVID-19 tests are.
While antibodies are present within a few days, testing for antibodies is generally more effective as long as ten to twenty days after symptoms in a patient. What’s not known is how long the antibodies remain present in our system after infection—and that’s the key to understanding the future of COVID.
So if a COVID antibody test isn’t used to diagnose infection of COVID-19, what do doctors and researchers use the test for? And who should receive an antibody test?
Antibody tests can be helpful in a couple situations when information about previous infection can help doctors address patients’ current needs. For example, an antibody test might help doctors diagnose multisystem inflammatory syndrome in children (MIS-C), a complication of COVID-19 that causes different body parts to become inflamed. By knowing a child had COVID, they can attribute current medical problems as a result.
Doctors and experts still have a lot to learn about COVID-19. And, even with vaccines available, there’s an urgency to learn as much as possible quickly. Because COVID antibody tests inform doctors when a patient has recently been infected, this data can be used to understand COVID’s spread in a given community, how many people were infected, and other general knowledge about the virus, giving doctors and researchers additional puzzle pieces to connect.
Antibodies created in response to the COVID virus act like guards once a person has recovered, and they can identify and fight off other COVID strains in your body, effectively helping to prevent reinfection.
Reinfection does occur with COVID, but in rare situations, and cases are extremely low in comparison to the overall number. This leaves doctors and researchers with more questions than answers to determine how effective antibodies are for immunity—primarily because we aren’t sure how long the antibodies remain in our system and how effective they are in combating reinfection.
Even after recovering from COVID, patients should adhere to preventative practices like wearing a mask when recommended and social distancing where transfer of the virus is possible or prevalent. Doctors and researchers still don’t know how long antibodies remain in the system to effectively fight reinfection. Some antibodies last longer than others. For example, our antibodies to the common cold don’t last long, and it’s possible to get sick several times from the same strain in that instance.
The FDA issued a Safety Communication in early 2021 advising doctors on current serological testing, and they reiterated that COVID-19 antibody tests should not be used to evaluate immunity because there are still unanswered questions and more research that needs to be done. This response was similar to a lot of what we hear in relation to COVID testing: we understand the information from each type of test is important and helps us better understand coronavirus, but more information is required.
At BioCollections Worldwide we understand the importance of testing. By learning more about infection—and who is and has been infected—we better understand viruses like coronavirus, their spread, and how to move towards immunization and control. Straightforward, affordable, fast testing is key. That’s what we provide.
With over twenty years’ experience in testing, we were as prepared for mass testing as anyone could be at the start of the pandemic. In fact, we were developing testing earlier than most, using our technology and experience to develop answers as quickly as possible. If you’re interested in a test, or just curious about how BioCollections works to provide the best in COVID-19 testing and research, contact us to learn more about how we can help.