Not All COVID Tests Are Equal: How to Choose the Best One for You

Nov 18, 2022
Not All COVID Tests Are Equal: How to Choose the Best One for You
In the past, you had two COVID testing options: Rapid results with less accuracy vs. waiting days for highly reliable results. Things have changed. Now you don’t need to choose between the two; you can get accurate results in hours instead of days.

Ever since COVID testing appeared on the scene, you’ve heard that you have two choices. You can get a fast but less reliable test or an accurate test that takes days to get results. But now you don’t need to choose between speed and accuracy.

The team at Path MD Labs performs several types of COVID tests, including today’s most advanced option, a highly accurate PCR test that produces results in hours instead of days.

There are two basic classes of COVID tests, viral and antibody. Here’s what you need to know about the different types and which one might be best for you.

Viral COVID tests

Viral tests reveal if you currently have an active SARS-CoV-2 infection. (SARS-CoV-2 is the virus that causes COVID.) You can get two types of viral tests:

Reverse transcription polymerase chain reaction (RT-PCR) tests

RT-PCR, or more simply PCR, is a type of molecular test that detects genetic material from the virus. The PCR, a type of nucleic acid amplification test (NAAT), uses a specific lab technique to identify the virus’s RNA.

Individual PCR tests are incredibly accurate. Positive test results (meaning you have the virus) are 100% accurate. Negative results that don’t find the virus’ ribonucleic acid (RNA) are accurate 98-99% of the time.

Antigen COVID tests

Antigen tests are commonly called rapid COVID tests. They produce fast results because they find proteins (antigens) released by an active virus. 

The accuracy of an antigen test runs about 30-40% lower than a PCR test, but it depends on the amount of the virus in your sample. A high viral load produces more accurate results, reaching 90%. 

Antibody COVID tests

An antibody test, also called a serology test, tells if you had a COVID infection in the past. This test identifies antibodies your body produced to fight the earlier infection.  

If you have COVID antibodies (positive test results) you may have some natural immunity. However, the strength of natural immunity and how long that immunity may last remain to be determined.

The current evidence shows that natural immunity wears off over time. The experts are still studying how effective natural immunity may be against new COVID variants.

How to choose a COVID test

Several critical factors have an impact on which COVID test is best for you:

Turnaround time

Thanks to the accelerated efforts of companies producing COVID tests, we now have PCR tests that can produce results in 3-24 hours, depending on which test you receive.

The standard PCR test still takes 2-4 days to produce results, but now you don’t need to choose between fast results and the accuracy of a PCR test.

If you have symptoms and need immediate results, or you need a COVID test right before entering a building or going to an event, you can get results in about 15 minutes with the antigen test.

Timing matters

Antigen tests only work if you have enough SARS-CoV-2 antigens in your body. If you get the test too early or too late, the results won’t be accurate.

For this reason, you should only have an antigen test if you have symptoms or you wait five days after known exposure to the virus.

By comparison, the PCR test finds RNA right after your exposure to the virus. You don’t need to have symptoms or wait. You can get a PCR test as soon as you or your doctor suspects you came into contact with an infected person or you were in a crowded environment where people had COVID.

However, there’s one exception. If you already tested positive for SARS-CoV-2, you need to wait 90 days before you can have a PCR test.

Convenient services for all COVID tests

No matter what type of COVID test you need, we make it as convenient as possible by offering drive-up and mobile testing. If you can’t get to the lab, we will come to you and take your saliva samples whether you’re at home or work.

If you have questions about or need to take a COVID test, call the Path MD Labs office located in the West Hollywood neighborhood in Los Angeles, or request an appointment online today.