Molecular Tests Detect COVID-19 Variants More Reliably than Antigen Tests, Study Shows

According to researchers, some variants can escape antigen testing entirely, and a negative result with an antigen test may no longer be enough.

In our last blog post, found here, we talked about a recent study that questioned rapid antigen tests' ability to detect Omicron when compared to molecular, also known as PCR, tests. The study showed that even when there was a transmission risk, the rapid antigen tests could not detect the Omicron variant. Whereas 28 out of 30 PCR tests accurately detected the Omicron variant. 

On the heels of that research, another study just came out that further affirms that there are limitations to relying on rapid antigen tests in comparison to PCR. 

The Study

In the study conducted at the University Hospital of Padua (Italy), researchers collected swab samples from patients who required COVID-19 testing with both a rapid antigen test and molecular test. They found the rapid antigen test, even with an overall sensitivity of 68.9%, could not detect COVID-19 in 19 out of 61 samples (31.1%).

As a result, researchers recommend that molecular PCR testing should be a priority across the globe in the diagnostic monitoring of COVID-19.

Why Use Molecular Tests

Rapid antigen tests are convenient and provide near-instantaneous results. Still, they have many downsides, including inaccuracy in asymptomatic or non-exposed populations, the frequency of false-negative findings, and no centralized reporting requirements.  

Despite the shift from molecular testing to antigen testing in many countries, this study further highlights the need for continued use of PCR tests for diagnostic monitoring, considering its capabilities compared to rapid antigen tests. 

Quadrant Biosciences’ Clarifi COVID-19 Saliva Test is currently the most sensitive PCR saliva test currently on the market. To date, our labs have distributed over 4 million COVID tests.   

Proposed Early Warning and Rapid Response Program

Quadrant Biosciences has submitted a proposal, currently being reviewed by New York State, to establish an early warning/rapid response program in the event that a new variant emerges.  Similar to a program already instituted in California, the program would involve periodic screening using the Clarifi COVID-19 PCR saliva test across the state to detect new transmission trends and immediately deploy broader testing if appropriate.  

Learn more about the Clarifi COVID-19 Saliva Test and how you can get tested by clicking here.