Could a simple blood test for COVID-19 antibodies help reopen the economy?

With a White House increasingly anxious to get the economy in gear and an approved vaccine for the novel coronavirus still months away at best, public health officials are hoping that tens of millions of Americans will have access to a simple blood test that can identify recovered patients who've developed some kind of immune response to the virus.

The idea behind the push is that people who have been exposed to the virus form antibodies in their bloodstream that may help them to fight off another infection. The hope is that the body's antibodies against COVID-19 can diminish the chances of re-infection. Theoretically, those found to have immunized antibodies could then return to work and help reignite the economy.

Commercial labs are scrambling to develop and distribute serologic tests, as they are known, in large quantities -- and the federal government is doing its best to expedite an approval process that is, under normal circumstances, lengthy and cumbersome.

Adm. Brett Giroir, tapped by President Donald Trump to lead testing efforts, said he is "very optimistic" that tens of millions of the tests will be available by May. And he says it could dramatically change what we know about the scope of infection inside the United States.

Tune into ABC at 1 p.m. ET and ABC News Live at 4 p.m. ET every weekday for special coverage of the novel coronavirus with the full ABC News team, including the latest news, context and analysis.

"That's really important as we think about re-opening the country and the economy because if you've had the virus and you've had an immune response to it, in all probability you are immune and safe from the virus," Giroir said on ABC's "Good Morning America" on Monday.

Others remain skeptical. Dr. Scott Gottlieb, the former head of U.S. Food and Drug Administration under President Trump, told ABC News he does not view the antibody test as a game-changer in the effort to reopen the economy. In reality, he said, relatively few people have been exposed to the virus.

"I think there's a perception that when we test the larger, general population that there's a lot of people out there who were exposed and have immunity," Gottlieb said. "But I think when we do these tests, we'll see it's actually much smaller."

Others on the White House coronavirus task force have put faith in antibodies as a way to reverse course in quick order. Dr. Anthony Fauci, director of the National Institute of Allergies and Infectious Diseases, has said he is "willing to bet anything that people who recover are really protected against reinfection," and Dr. Deborah Birx, the White House task force coordinator, said she has "called on every university and every state to develop [antibody test capabilities]."

Testing troubles from the start

The U.S. has struggled in determining who is infected by the novel coronavirus. The country's ability to track outbreaks of flu virus is done largely by public health labs that don't have the resources to conduct widespread diagnostic tests.

The federal government eventually brought in the private sector as part of a coordinated response. But by then, the virus was spreading rapidly and the complicated diagnostic tests that required specialized equipment wasn't widespread enough to figure out who had the virus – prompting the need for "social distancing" rather than containment.

Now, health officials are urging Americans to reserve diagnostic tests for the active virus – a nasal swab – for health care workers and patients in hospitals.

The approach raises urgent questions though about how long social distancing can be maintained, especially considering the blow to the economy and families struggling to get back to work.

"There's tremendous light at the end of the tunnel," President Donald Trump promised late Monday, citing new developments in research.

Antibodies as treatment

Multiple healthcare institutions around the country are using blood antibody tests to identify potential donors for a therapy called convalescent plasma. The experimental treatment pulls blood plasma from recovered patients and injects those antibodies into the sickest patients, with the goal of staving off the disease.

"We believe it can be disease-modifying and reduce duration and severity in some patients," said Dr. Michael Joyner, a physiologist and anesthesiologist at the Mayo Clinic, one of the institutions who has started the collection process for COVID patients who may qualify.

While researchers move forward with convalescent plasma treatments as a stop-gap measure, the simple blood test that can tell a person if they have the antibodies is being strongly considered as a public health tool to understand how many people may already have had the disease.

On Tuesday, FDA Commissioner Dr. Stephen Hahn said antibody testing can help identify individuals who have overcome an infection and that "may potentially be used to help determine, together with other clinical data, that such individual are no longer susceptible to infection and can return to work."

Those found to have sufficient antibody immunities could begin trickling back to work and eventually start getting the country – and economy – back to normal. Experts say the antibody test could be an invaluable marker to identify those recovered patients.

"The antibody test will tell us what happened in the past and will also help us in the future as a potential therapy," said Dr. Arturo Casadevall, the chair of molecular biology and immunology at Johns Hopkins, told ABC News' Diane Sawyer. "So I do think that we need to redouble our efforts to deploy rapid antibody tests to know who has been infected and who has overcome the virus."

Federal regulators say they won't stand in the way

In March the FDA allowed developers of the antibody test to market their antibody tests without FDA review as long as certain conditions were met.

"The important thing is for the people who have this test -- and I stress that some companies are developing them, and they're also being found in academic centers -- to work with the FDA so that this test can be done very rapidly," Casadevall said.

The FDA has said it doesn't intend to object to the development and distribution of these serology tests either. At least one company – Cellex – has gone so far as to receive "emergency authorization."

The FDA has said it can authorize antibody tests under an emergency use authorization. At least one company – Cellex – has already received that authorization. A spokesperson for Cellex told ABC News that the company "is optimistic that 100,000 test kits will be shipped very soon from China to New York City."

Industry, academia stepping up

The result is that several commercial labs have entered the race for a workable, scalable test.

New York-based United Biomedical partnered with San Miguel County, Colorado, with a goal of testing all 8,000 county residents for antibodies. As of yesterday, over 1600 tests were processed and only 8 people so far have tested positive for antibodies. Full test results are expected in the coming days and the company said it already has plans to test other communities around the country.

BioMedomics, a North Carolina-based firm, is also developing a so-called rapid test – with results available within 15 minutes. The company is working with BD, a medical tech company, and Henry Schein Inc. to distribute the tests.

The FDA said Monday it had received requests from more than 100 companies for emergency authorizations for antibody tests – Cellex being the first to receive authorization. United Biomedical also told ABC News it was seeking authorization.

As of Wednesday, 70 commercial labs had notified the FDA that they have antibody tests available for use but without proceeding with an emergency use authorization. BioMedomics is on that list.

Researchers at academic centers like Stanford have also experimented with mass serologic testing. Over the weekend, the university's health policy arm collaborated with the Santa Clara County Department of Health to administer serologic tests to 3,200 people in the area.

With all the private companies and researchers racing to develop and deploy tests -- and the FDA scrambling to cut out bureaucratic red tape – risks with faulty products persist.

"It's a balance for the FDA to get things out quickly, and there has been a lot of pressure and lot of push to get tests out," said Dr. Angela Caliendo, an infectious disease expert at the Brown University medical school, describing the FDA's use of emergency authorizations for serologic tests.

"To get [tests] out quickly means you don't have a clinical study," said Dr. Caliendo, who is also the secretary of the Infectious Diseases Society of America. "So the upside is we have the tests. The downside is we don't exactly know how well they're going to perform."

Adm. Giroir echoed that sentiment, noting that the volume of labs rolling out their own tests made it increasingly likely that some won't work.

"'Approved' is not a word we talk about," Giroir told reporters. "There is a test or two that has received emergency use authorization and many, many, many others out there that have not gone that way yet, and I want to take this opportunity to caution."

The FDA on Tuesday warned that some firms are "falsely claiming that their serological tests are FDA approved or authorized."

But will they work?

As for millions of faulty tests already on the market, Giroir said "we're not going to get in that situation."

Scott Becker, the CEO of the Association for Public Health Laboratories, said he has raised the concern of faulty tests with the federal officials – including Giroir. To their credit, Becker said, the FDA, CDC, and National Institutes of Health have responded well and indicated that they plan to roll out a government validation panel to review tests in the coming weeks.

"The last thing we need right now is bad tests on the market," Becker said. "You do not want to provide a bad result. We need to ensure that whatever tests Americans are going to get have a high degree of accuracy.

The other question is who gets access to the tests. Giroir said he wants health care workers and the elderly to have first dibs. But with the private sector running the show, it's unclear how the government would enforce that – possibly authorizing a specific company to test high-risk populations.

Meanwhile, another race is on within the biomedical community that will eventually nullify the need for antibody tests and treatments: a vaccine.

But with a possible vaccine still far beyond the horizon, the serologic testing could be fastest way for Americans to regain some sense of normalcy before the fall respiratory infection flu season begins again.

What to know about coronavirus:

• How it started and how to protect yourself: coronavirus explained
• What to do if you have symptoms: coronavirus symptoms
• Tracking the spread in the US and Worldwide: coronavirus map