There are two major types of tests for COVID-19, and a lot of us are still confused about the crucial differences between them. So let’s explain it with a little help from our fearless founder, Dr. Juan.
Diagnostic or “PCR” Test
Put very simply, this is a test that looks for the living virus in your system. The test works on the molecular level to find the genetic material of the virus.
A good analogy might be if your husband or wife steals bread from the kitchen and goes to eat it in another room. You notice, and walk into the room and say, “Hey, did you take that bread?”. It’s obvious they did, because the bread is in their hands. You caught them red handed. That’s the PCR test. It will tell you if the virus is active in your body.
A PCR test is incredibly accurate, and there are far fewer, if any, false positives. These tests often take a little longer to turnaround results because it’s hard to identify the genetic material of such a tiny virus like COVID-19.
But a PCR test isn’t going to tell you if you’ve already had the virus. Just like walking into a room to confront your spouse isn’t going to catch them if they’ve already eaten the bread. They might have already swallowed the evidence!
In that case, you’re going to have to look for other signs to tell you they’ve already eaten the bread - or had the virus, in terms of our analogy - and that brings us to our second type of test, the antibody test.
The Antibody Test
An antibody test looks in your blood for signs that your body has produced the unique type of antibodies for COVID-19. It doesn’t actually look for the virus itself. It looks for evidence in the body that you have come in contact with the virus.
To continue our analogy of marital thievery, this would be the equivalent of not catching your spouse with the bread but noticing that they have bad breath, which they ALWAYS get after eating stolen bread. “I know you ate that bread because I can smell it on your breath. Time to come clean!”. It’s not a perfect analogy, because of course in real life we can get bad breath from a lot of things. But in the case of COVID-19, you can only produce COVID-19 antibodies if you’ve been in contact with the virus.
This means that the antibody test is really good at telling us if we have had the disease, but not so good at telling us when we have had it, or if we still have it. If you test positive for an antibody test, it’s possible that the antibodies in your blood are there because of an active infection. It’s also possible that they are present because you were asymptomatically sick 3 months ago.
Timing and Type
What does all this mean? It means that the timing of your test, and the type of test you decide to take, are extremely important to determining if you should quarantine, or even go see a doctor.
Dr. Juan walked through an extremely helpful graph of the way the two types of COVID-19 tests work together from a timing perspective, along with a wonderful explanation of the tests themselves. We’ll let him take it from here.
Let’s get healthier together,
Your friends at Santo Remedio
