On Thursday, the first COVID-19 antibody test, the “qSARS-CoV-2 IgG/IgM Rapid Test”, was approved by the United States Food and Drug Administration (FDA). Cellex Inc., a biotechnology company, has created the antibody test. May Clinic is also in development for their own antibody test, which will be released April 6.
What would this antibody test potentially do? It could see if someone has ever been has ever been exposed to SARS-CoV-2 (aka COVID-19). It could possibly even tell if they are now immune to to the virus. Along with Seema Sarin, MD, board certified Internal Medicine physician at EHE Health, we did an interview with WELL + GOOD about antibodies and how these tests are different from the COVID-19 testing kits.
Antibodies are part of the immune system that identifies what’s called an antigen, which is a bad guy. White blood cells produce antibodies in response to bad guys, or a virus, bacteria, or fungus. The antibodies mark the bad guys so that the immune system can more easily target them and eradicate that invader. Antibodies attach to the pathogens like viruses and neutralize them, stopping them from duplicating.
Antibodies attack bad guys they’ve met before, whether from a prior illness or vaccine. There are different forms of antibodies. For example, the ones that target a strain of the flu is different mumps or measles. This applies to SARS-CoV-2 as well. Anyone who has already had the virus would have produced specific antibodies to fight it off in the future.
“The [antibody] test works by testing your blood for coronavirus antibodies to see if they have already beaten the virus and gained some immunity to it,” says Dr. Sarin. This is called serologic testing. The Cellex test takes blood from a person’s veins while some other types of antibody tests take blood using a finger prick. Tests like these have been used for antigen p24, an indicator of HIV. It’s also been used for research purposes with seasonal influenza.
The Cellex test looks for two categories of antibodies called immunoglobulin M (IgM) and immunoglobulin G (IgG). Your immune system releases the first, IgM, when it is fighting a new infection. It releases the second, IgG, later to fight the specific bad guy. Testing positive to this testing means you’ve been exposed to SARS-coronavirus-2 and possibly immune to it.
When you hear about testing kits for COVID-19 in the news, they’re not talking about antibody testing. The test they’re talking about is design to actually identify the virus, which they call a viral antigen or a vision, in the body. They do that with something called polymerase chain reaction (PCR) technology. Essentially, what they’re doing is looking for these pieces of the virus in the body and saying, ‘oh yeah you’re infected’ or not. That’s very different than finding someone who’s already been infected and may not have known it.
Dr. Sarin explains that these tests require about 24 hours to go to a testing lab and return back to a medical facility with patient results. In contrast, antibody tests only take 15 minutes to show results.
This is simply identifying those people who have made the antibodies, and therefore it's assumed that they've been exposed to the virus previously.
Dr. Rand, DOChief Medical Officer of Live Cell Research
We don’t have a vaccine yet. We don’t have a treatment so far that’s been confirmed so far with ideal gold standard trials. This is simply identifying people who have made the antibodies, and therefore it’s assumed that they’ve been exposed to the virus previously.
Virologist Angela Rasmussen, PhD, explained in the New York Times that this is a possibility but not a guarantee. Having antibodies is not the same as having effective antibodies. One time exposure doesn’t last forever, which is why you periodically need to get revaccinated for viruses. Because the virus is so new, there isn’t a lot of testing on long-term protection.
In our experience with other coronaviruses—and we’ve got five of them in our history other than the SARS and the MERS that we can go back and see—is that the odds are very strong that you won’t get infected for at least another year. Other experts estimate it could even be two to three years, but at this point it is not a certainty.
The problem is, some of these viruses, like the flu, mutate. Every year we have a new strain. Immunity against this year’s strain would be less valuable if SARS-CoV-2 mutates.
The cool thing about that though, is because the viruses have mutated, they’re still somewhat similar. So, even if it was a mutated strain, you’re likely to have a better immunity than someone who’s never been inoculated with that virus.
Medical experts are excited for the antibody tests because it can change things for the medical community. 25% of individuals who’ve contracted the virus are asymptomatic, and around 80% of cases are believed to be mild. This means there are likely plenty of health-care professionals who have contracted the virus, built up antibodies, and could be potentially immune.
There are people out there who are risking their lives, literally. If we can identify that they’ve already inoculated the virus, and are therefore potentially, immune, then the fear of getting sick doesn’t have to add stress to everything else going on. They can also go into work without a mask, so they don’t have to waste supplies. We can put those people on the front lines, and those who don’t have the antibodies we can choose to be more careful with.
If someone has developed immunity to the disease, this virus, what they're able to do is extract these antibodies and give them to somebody else so that they can better fight the disease.
Dr. Rand, DOChief Medical Officer of Live Cell Research
The benefits go past the medical community as well. People are being told to stay home, and in doing so may be losing their jobs, losing income, or may just be frustrated that they can’t get out and about to do exercise, or whatever it is. Testing positive to the antibody test could potentially give someone the okay to go back to normal activities.
“Such a test may help scientists learn how widespread the infection is, and how long people remain immune after recovering,” says Dr. Sarin. Larisa Labzin, PhD, of the Institute for Molecular Bioscience at The University of Queensland, told The Conversation that the test could also give experts a better sense on who is prone to the infection and why, in turn helping develop future prevention and treatment guidelines.
This research could possibly be helpful when it comes to antibodies as well. Meaning, if someone has developed immunity to this disease, this virus, what they’re able to do is extract these antibodies and give them to somebody else so they can better fight the disease.
That’s something that would have to be done voluntarily by those people, but we’re all humans, and I can’t imagine that there will be anything less than a fairly large percentage of the population who would want to donate their plasma. Clinical trials on plasma therapy for COVID-19 are already in the works around the United States.
Even though the FDA and Mayo Clinic have approved the testing, its distribution is still up in the air. More than likely, if we’ve got our head screwed on straight here, the first people to get these kits will be health-care practitioners. Beyond that, I would think other essential workers would be next on the list: people working in the grocery stores and driving public transportation. I would hope that that would be the way antibody kits were rolled out.
In the U.S., kits will likely be administered in certified doctors’ offices or via telemedicine if possible. The UK is considering the opposite. They’re talking about selling the antibody testing kits on Amazon, and doing a 100,00 kit rollout to see how that works.
You can see why I’m jumping up and down about this, because I think it’s just that we’re overwhelmed right now with treating people who are sick as best we can, and also finding a vaccine for next year. But there’s a middle ground in there, which is: Let’s get these antibodies tested.
In the meantime, learn how to limit exposure when grocery shopping or ordering takeout.