EL SEGUNDO, Calif. — Thanks to the coronavirus, you don’t need a crystal ball to tell you that until a vaccine is found a lot of us will most likely have some kind of test in our future to make sure we’re keeping those around us safe. And the tests themselves, well they seem more than a little confusing! Which test to take? So, come with me, let’s get virtual and find out.
There are three different types of tests: genetic, antigen, and antibody.
To keep it simple let’s think about these tests in terms of when they’re used.
If you want to know if you have the virus because you think you have symptoms — you take the genetic and antigen tests. If you think you’ve had the virus in the past, then you take the antibody test.
Let’s look a little closer.
If you think you have coronavirus symptoms right now, then you take the genetic test — sometimes called PCR, which is a molecular, swab down of the back of your nose. The test will check if any of the genetic material from the virus is present in you. Nice! Because the virus’s genetic sequence, its special code, is widely known. If it’s there, doctors can match it and recognize it and tell you so that you can take action right away. This test can take hours or sometimes a day or so. It’s not fast but it’s fairly accurate.
Another test to tell if you have an active infection right now is the antigen test, which isn’t at the moment readily available. It too is a swab down the nose test but this time it’s looking for the presence of specific proteins on the surface of the virus. The proteins are easier to spot. So, it’s cheaper and faster like a test for strep-throat at the doctor's office and could be something used quickly at home or at work. At the moment, it’s not so accurate and could give you a false impression that you’re virus-free to go back to work when in fact you’re not! So, for obvious reasons, there’s still a lot of work to be done.
If you think you’ve had the coronavirus in the past, then you take the antibody or serology test because your immune system will have created antibodies to fight off the virus. It’s a useful test to determine if you’ve had it because some people don’t have any symptoms at all — they’re asymptomatic. The test can also help tell us how many people have had the virus and if we’re winning the battle against it. Also, if you’ve had it, you might have immunity from getting it again although there are no promises and you can also donate your blood plasma to help others fight off full-blown COVID-19. The problem with this test is that a specific set of antibodies can turn up two weeks after infection, which means if you test for antibodies at the wrong time it might seem that you haven’t been infected at all, when in fact you have. And some people might not even develop antibodies at all. So this test is a little less of a sure thing.
In fact, these tests are not 100% accurate because this is a new virus. And creating accurate tests take time. Rushing at it leaves us open to making mistakes or creating ineffective tests and vaccines so we need to allow our scientists time to learn all they can about this tricky and mischievous virus so that one day, like smallpox, COVID-19 will be a thing of the past.