SHARON — As society slowly emerges from the COVID-19 quarantine, the question on the minds of many people has shifted from “Do I have the virus?” to “Did I have the virus?” — and therefore, do I have immunity from reinfection?
Even as antibody tests become available, uncertainty surrounds the issue, including how much protection is offered even if someone tests positive for COVID-19 antibodies.
“Right now, no one knows what the presence of antibodies really means,” said Dr. Mark Hirko, president of Sharon Hospital, where FDA-approved serological, or antibody testing, is now offered.
“Are they safe from reinfection? Safe from not being contagious?”
Currently, he said, there are no clear answers. Even if antibodies were found to provide immunity, Hirko said, it is not known how long that protection would last.
Antibodies are proteins made in response to infections, such as COVID-19. They can be found in the blood of people who are tested after infection, showing that they have had an immune response to the coronavirus.
But some health professionals, and the Centers for Disease Control and Protection (CDC), caution that rushing out to get tested for antibodies is not advisable, as the test has limitations.
“This test is not currently designed for individual use … to test people who want to know if they have been previously infected with SARS-CoV-2,” according to the CDC. Rather, the serologic test has been “designed and validated for broad-based surveillance and research purposes, to provide information needed to guide the response to the pandemic, and protect the public’s health.”
Not all tests are alike
Sharon Hospital, said Hirko, “is the only hospital in the Nuvance Health system offering the antibody test,” which aids physicians in determining who may be eligible to donate a part of their blood, called convalescent plasma, which may serve as a possible treatment for those who are most seriously ill from the virus.
Although a number of commercially manufactured antibody tests that check for the coronavirus are available through health-care providers and commercial laboratories, Hirko said Sharon Hospital is “using the test that received FDA approval,” as are other hospitals.
The test requires a blood draw, as opposed to other methods that may use a sample of blood taken from a finger prick or a swab test. There are hundreds of antibody tests out there that you can order online, Hirko cautioned, “but it is unknown as to the FDA approval status of the myriad of testing equipment available on the internet.”
As Connecticut navigates its initial phase of reopening businesses, and in response to individuals and employers who see antibody testing as part of reentry into society, several statewide urgent care clinics have reported they are also offering antibody testing.
False sense of security
Hirko said that unlike the nasopharyngeal tests used to diagnose COVID-19, antibody tests at Sharon Hospital is not free of charge and might not be covered by insurance. A prescription is required; the patient must not have symptoms of the virus or if they suspect they have been exposed to the virus, they must wait 10 days before testing.
The Sharon Hospital president cautioned that while the antibody tests seem to be more reliable than the viral diagnostic tests, the hospital does not want to give people a false sense of security should they test positive for antibodies.
“Nasal swabs have been very accurate. The Abbott rapid studies have a 12 percent to 48 percent false negative rate, which is not good, and this study [of the antibodies] is a lot more accurate — in the 90s and even higher,” said Hirko.
Sailors reinfected?
Even so, Hirko offered this caveat, which he said is worrisome: The U.S. Navy has reported that five sailors from the virus-stricken USS Theodore Roosevelt who had recovered from COVID-19 and received two negative test results, recently tested positive for a second coronavirus infection.
That brings the total of reported reinfected crew members to 13, according to the Navy. It remains unclear whether the tests were faulty, or if the sailors were reinfected aboard the ship, docked in Guam.
In a statement, the Food and Drug Administration said that, “At this time, it is unknown for how long antibodies persist following infection and if the presence of antibodies confers protective immunity.”
The hope is that ultimately the test will aid researchers in better understanding how widespread the coronavirus is.
It is unlikely, said Hirko, that scientific research on antibodies will become available for at least one year to 18 months.
“Right now, we are four months in with a brand new virus. It’s hard to fathom, we have so many things to figure out. We don’t know what the threshold is that would confer immunity. That is the great unknown.”
