Coronavirus: Make Sure The Test Covers New Variants, Experts Say

A year after Hudson Valley residents were introduced to the intricacies of coronavirus testing, a new factor when it comes to getting tested has popped up: variants of the virus may have changed enough to possibly evade detection by some tests on the market.

The U.S. Food and Drug Administration issued an advisory letter to health care providers in January, mentioning three brands of PCR Covid-19 tests with emergency use authorization that may not be able to reliably recognize newer variants of the virus.

The so-called "U.K. variant" was first identified in the Hudson Valley in January, and the South African variant was found in New York City this week, along with a newly-identified homegrown New York City variant.

Kara Cannon is the chief commercial officer at Enzo Biochem, which has a lab on Long Island. She told Patch that they've been warned by the FDA to evaluate how their tests perform when it comes to detecting samples with these new variants. She says their testing can pick up these new strains because they created a general enough test last spring.

Enzo's tests are used by medical providers and pharmacies in the Tri-State area.

New York State Department of Health collects samples from all coronavirus testing labs, to identify and track the emergence and spread of new strains. When the pandemic first hit, the state was collecting data daily; now labs must be report updates every three hours, Cannon said.

As of now, there is no way to know what strain of the virus you test positive for, but it's possible that as new strains become established and coronavirus possibly becomes endemic, like the flu, and if certain strains become associated with different outcomes, labs will begin to regularly sequence tests, Cannon said.

For now, anyone getting tested should ask their doctor if the brand of PCR or rapid test they are using can detect these new variants.

The notice from the FDA mentions three brand names—Accula, TaqPath and Linea—that may have reduced sensitivity, leading to false negatives, due to some of the mutations in the newer strains. As new strains continue to emerge, labs, providers and patients will have to continuously be monitoring for new information that might affect the accuracy of tests, however.

"Every manufacturer and provider has to think about this," Cannon said.

By Jacqueline Sweet, Patch Staff