Breaking News
More () »

Houston's Leading Local News: Weather, Traffic, Sports and more | Houston, Texas | KHOU.com

Which COVID-19 tests are most accurate?

Dozens of tests are authorized by the FDA, but that doesn’t mean the results are validated.

HOUSTON — There are several ways to find out if you’ve been infected with COVID-19.

Dozens of tests are authorized by the FDA, but that doesn’t mean the results are validated.

So which are the most accurate?

Doctors say tests fall into two categories: ones that show if you have COVID-19 now and tests that detect if you’ve ever had the virus.

PCR tests and antigen tests tell you if you’re infected now.

Antigen tests detect certain proteins and are typically rapid tests. PCR tests amplify genetic materials to detect small quantities of the virus in active infections.

Dr. Michael Chang, infectious disease pediatrician with UT Physicians/UTHealth, says PCR tests are thought to be more reliable.

“I was checking the FDA’s site. There are around 32 authorizations for PCR tests right now. They can be nasopharyngeal swabs meaning the high up swab, nasal swab which is a little further out, or saliva,” he explained. “Generally speaking, we think of PCR tests as having better performance than antigen tests”

Antibody tests, or serology tests, show if you’ve been infected with the virus in the past. Antibodies are proteins your body makes to help fight infection and develop immunity.

It can take two weeks for antibodies to be detected after being infected with the coronavirus.

“I think there are something like 60 authorized antibody tests. As far as I know, the FDA has only validated about 12 of them. The validated ones are all blood tests you have to send off to a lab and they have to perform in a lab,” said Dr. Chang.

The bottom line is Dr. Chang recommends a PCR test if you think you’re sick. He says all are more accurate if you get tested when you have symptoms.