COLUMBUS, Ohio (FOX19) - The antigen test Ohio Gov. Mike DeWine took Thursday morning that returned a positive result for COVID-19 is not widely used in the state, according to Peter Mohler, MD, chief scientific officer for The Ohio State University Wexner Medical Center.
If you’ve been tested for COVID-19 in Ohio, you’ve likely gotten a PCR test, which Mohler said represents the “gold standard” of COVID-19 tests and is more accurate than the antigen test “by far.”
Mohler spoke Friday afternoon during the governor’s media briefing on the status of COVID-19 in Ohio.
DeWine tested positive for COVID-19 off an antigen test arranged by the Republican National Committee Thursday morning prior to a scheduled meeting with President Donald Trump, which did not occur. (Previously DeWine had said the test was organized by the White House.)
The antigen test was manufactured by Quidel, one of just two companies that currently makes antigen tests.
DeWine later took a PCR test that was run twice at the Wexner Medical Center and came back negative both times.
Explaining the strengths and limitations of each test, Mohler likened the antigen test to a pair of binoculars and the PCR test to a high-powered telescope.
The PCR test is decades-old and highly accurate. It looks for the coronavirus’s specific RNA and is so sensitive it can detect even low-level viral loads in asymptomatic carriers, Mohler explained. But it’s difficult to scale and takes between several hours and a few days to return results.
The antigen is a brand new type of test, Mohler said. It returns results in a matter of minutes, making it useful for contact tracing and quick quarantining of those infected. But it has a significant drawback, as the state of Ohio learned Thursday, in that it’s less sensitive and therefore less accurate than the PCR test.
(Curiously, Mohler said a false positive from an antigen test is atypical.)
That’s not to say antigen tests don’t have their place in a state’s testing toolkit, Mohler added.
Nor are antigen tests the only type of rapid test available, as he described an Abbot Labs test that can be returned within an hour and is closer to the PCR test in terms of accuracy.
But the PCR test remains the “best and most accurate test in the world,” Mohler said, and it’s the type used by the vast majority of Ohioans.
Of Ohio’s 1.6 million COVID-19 tests performed since March, including the 22,000 it performed per day in July, upwards of 90 percent have been PCR tests, Mohler said.
But that could soon change.
DeWine announced Wednesday Ohio had entered into a multi-state purchasing agreement with Maryland, Louisiana, Massachusetts, Michigan and Virginia to expand use of so-called “rapid point-of-care tests.”
He said at the time: “This will help us detect outbreaks sooner with faster turnaround time, expand testing in congregate settings and make testing more accessible for the most high-risk and hard-hit communities.”
To be clear, “rapid point-of-care” tests is a broad category of which the antigen test is just one member. The Abbot Labs test would also fall into that category.
But DeWine acknowledged Friday antigen tests were intended as a part of that purchase agreement.
After the “rollercoaster” of Thursday, though, now he says he’s having second thoughts.
“If we’re going to deploy an antigen test, we’ve got to think long and hard about how we deploy it,” he said.
He added the multi-state agreement is merely “looking at” the antigen test and has not entered into a legal purchase contract at this point.