The vast majority of those who’ve recovered from COVID-19 make antibodies capable of neutralizing the deadly virus, according to new research from the Icahn School of Medicine at Mount Sinai in New York.
The research, posted Tuesday but which has yet to be peer reviewed, could breathe new life into widespread antibody testing, once heralded as a tool to help reopen New York’s economy. When reliable, the tests offer insight into what percentage of the population has been infected, can aid in treatment, and may give patients who do have the antibodies some peace of mind, as a growing body of research indicates they could be immune to reinfection for at least some time.
“Here is some good news. The majority of people who recover from COVID-19 have high titers of antibodies,” said Dr. Arturo Casadevall, an immunologist who is leading research into experimental treatments using convalescent plasma at Johns Hopkins University in Baltimore, at a news briefing on Thursday. Convalescent plasma, or blood plasma from a recovered patient, could potentially be used to help infected patients with severe or life-threatening symptoms.
Casadevall said researchers at Mount Sinai Hospital developed an extremely accurate antibody test, which has shown most people are producing the proteins at levels high enough to neutralize the disease.
“The majority of people that have recovered have the antibodies, and out of those people, the majority have neutralizing antibodies,” Casadevall said. “It means that the majority of people who are recovered have in their blood something that is associated with immunity.”
Gov. Andrew Cuomo had initially emphasized antibody testing as paramount to getting New York back online, calling the tests “the new ventilators,” until questions over their reliability and whether patients are truly immune after having had the virus caused the state to reconsider.
But the research released this week makes the prospect seem more likely. The study by researchers at Mount Sinai found that all but two of 624 people tested with previously confirmed diagnoses produced antibodies in the weeks following infection, “potentially providing immunity to reinfection,” the researchers wrote in the abstract.
If researchers are able to determine that people who have the disease can’t catch it again, antibody testing could again be a top priority.
The state has already started the process of testing. New York state announced the latest results of its antibody testing study on Saturday. It tested a random sampling of 15,000 people at grocery stores and community centers in late April. The results found 12.3% of the state population have COVID-19 antibodies. In New York City, almost 20% of the population had them, according to the state health department.
Testing for essential workers is already available at hospitals and other locations. But when and if reliable testing becomes available on a large scale, city officials will still face a challenge in administering the tests across all areas of the city.
New York City’s Health + Hospitals Corp. has been working with the Centers for Disease Control and Prevention (CDC) to test up to 140,000 health care workers and first responders. But the city plans to double that number by administering tests to other New Yorkers over the next few weeks, Mayor Bill de Blasio announced Thursday.
An additional 140,000 tests will be handled by New Jersey-based BioReference Laboratories, according to de Blasio. Up to 5,000 people could receive the free test daily, de Blasio said, or about 70,000 in the next few weeks. Five testing sites will be set up initially, located in Morrisania in the Bronx; Long Island City, Queens; upper Manhattan; Brooklyn’s East New York and Concord in Staten Island.
More than 1 million cases of the virus have been reported in New York state as of Thursday, with nearly 21,000 fatalities. In New York City, there have been more than 180,000 reported cases and 14,248 deaths.
Reliability and scalability
The tests come with big caveats.
Many commercial antibody tests are only 50% to 60% sensitive, according to Dr. Lydia Dugdale, an associate professor of medicine and the director of the Columbia Center for Clinical Medical Ethics.
“If the test is 50% sensitive at the time, it’s not even detecting the stuff we want it to detect,” she said. Tests for COVID-19 antibodies can also inadvertently detect the common coronaviruses that cause less severe colds.
If a reliable antibody test were available, there are additional bottlenecks in administering the tests, Dugdale explained. For starters, there would have to be enough test reagent available. And then there is the question of how many and how quickly labs can process those tests once blood samples are obtained.
The U.S. Food and Drug Administration (FDA) issued revised guidelines for antibody tests on Monday, now requiring companies that make them to apply for emergency-use authorization within 10 business days of their products hitting the market. Those whose tests are not sensitive enough or specific enough for the COVID-19 virus will be required to suspend distribution, according to the organization.
More uses of the testing
The tests can certainly be useful in the future, according to Dr. Arthur Caplan, head of the division of Medical Ethics at the NYU Grossman School of Medicine.
That’s especially true if there is another wave of the virus in the fall or winter.
“At least you know who you really have to pull out of the workforce, who you might say can go back in as long as they’re wearing a mask,” he said. “I think it would help in case the thing bounces back and we faced another strain on resources.”
But keeping track of who has had the virus and who has not will be another issue. Immunity passports, which indicate a person’s health history, are one option. These certifications could help people move more freely in the future, while allowing those with the passport to know they are not spreading the virus.
Other countries, like Germany, are also looking into immunity passports. These could eventually morph into certifications that prove vaccination, should one become available, Caplan added.
Some point to these passports as potentially intrusive, but Caplan doesn’t agree.
“It’s not like you’re going to get stigmatized or penalized,” he said. “What you get is a reward. And if you’re found to be not immune, it doesn’t mean you can’t come out, but it means we want to keep an eye on you just to make sure you don’t catch the virus.”
However, even if penalties are not imposed on a government level, businesses could require an immunity passport for employees, Caplan noted. As could places like sports arenas, theaters and bowling alleys—anywhere that attracts large gatherings.
“I can imagine a movie theater saying, ‘you don’t have this, you’re not coming in,’ or even your workplace saying,’ if you don’t have it, you’re not coming to work,’” Caplan explained.
That could create a disparity between those who have the passport and those who do not. People without immunity may be passed over for employment, but it might be necessary.
“We’re in a plague,” Caplan said. “It’s not the same as having a disability. It’s a little bit more like saying, ‘if you come to work here and uh, you have the flu, I want you to go home.’”