Testing for the presence of COVID-19 antibodies in people who believe they may have contracted the Wuhan Coronavirus and subsequently recovered will begin this week, according to the Centers for Disease Control and Prevention.
The screening, known as serology testing, will be given to three groups of individuals to determine whether they fought off the infection without ever having a positive test for the illness. Experts across the globe have suspected that numbers of infected people are much higher than positive tests have confirmed because of a belief that many survived the course of the illness without symptoms.
Other people with mild symptoms who may have been infected were advised to stay home if they were not in need of urgent medical care, which could also increase the number of previously undetected cases. In an effort to enhance data on the nature of COVID-19 and detect potentially immune people, the Food and Drug Administration issued a single Emergency Use Authorization to private laboratory Cellex, Inc. to green light their new serology test. The CDC confirmed that the test would be implemented immediately.
"Based on the totality of scientific evidence available to FDA, it is reasonable to believe that your [Cellex Inc.’s] product may be effective in diagnosing COVID-19,” the CDC wrote in its official authorization. “The known and potential benefits of your product when used for diagnosing COVID-19, outweigh the known and potential risks of your product."
The test will be administered to three groups as a survey, according to the CDC, beginning with those that have not been positively diagnosed in "hot spot" regions but believe they may have been exposed. Hot spot regions will include places like New York City that have seen the most extreme number of cases in the United States, followed by other metropolitan areas with large populations. The second and third groups to receive serology tests will be in other, less effected regions.
Data gathered by the three phases of surveillance testing will provide critical data about how many people have been exposed to the disease without symptoms that have required hospitalization. The results could help local leaders and the federal government determine guidelines about reopening certain businesses and industries curtailed by stay-at-home orders.
White House Coronavirus Task Force members Drs. Deborah Birx and Anthony Fauci have both touted the potential benefit of getting serology testing to the marketplace. Dr. Birx has said that the test could mean that those proven to have fought off COVID-19 are "99.9 percent" certain to be immune from subsequent infection by the virus, which possibly opens the door to a return to the workforce; such results could be a significant relief to exposed healthcare workers sidelines by quarantine.
New York State warned that although testing would begin in certain areas, the product was not a guarantee of immunity and was not approved by the FDA.
"Newly available tests to identify antibodies to SARS-CoV-2 are of uncertain reliability and may be inadequate in diagnosing acute COVID-19 infection," a statement on the government website noted. "The Food and Drug Administration (FDA) is now allowing manufacturers to distribute diagnostic serology test kits as long as the manufacturers state that the assay has been validated. The FDA is not independently assessing these tests for reliability, sensitivity, or specificity, or requiring an Emergency Use Authorization."