Virus antibody test hopes on hold
Bold predictions of return to normalcy remain unfounded
WASHINGTON — At the height of the coronavirus lockdown, President DonaldTrumpand his top health advisers trumpeted a new test thatwould help Americans reclaim their lives— one thatwould tellthemif they already had the virus and were protected fromgetting it again.
Their arrival would help “get Americans back to work” by showing those who might have “the wonderful, beautiful immunity,” said Trump, a point repeated at daily briefings in April.
Months later, the U.S. leads theworld with nearly 190,000 deaths and over 6.3 million infections from COVID-19, according to Johns Hopkins University data. While the country is awash in the tests, the bold predictions about their usefulness have yet to materialize. “There was definitely a lot of wishful thinking that there was going to be a magical test that was going to save us all, but we’re not there yet,” said Dr. Jennifer Rakeman of New York City’s Public Health Laboratory.
The tests check the blood for antibodies the body makes to fight off an infection. Scientists are still working to figure out how well antibodies for the coronavirusmay shield someone fromanother infection, or howlong that protection might last.
For now, the Centers for Disease Control and Prevention and the American Medical Association warn that antibody tests should not be used to make decisions about returning workers to the office or students to school, though some labs still promote them for those uses. The CDC recommends everyone— even those whowere sick and recovered — take precautions to prevent getting and spreading the virus.
Experts say it was probably unrealistic to expect answers to key immunity questions early in the outbreak. Those questions have traditionally been answered only through longterm animal or human studies, said Marc Jenkins of the University of Minnesota.
The National Institutes of Health and universities are conducting some of this work, but much of it has taken a back seat to the rapid development of vaccines in a pandemic.
“Everyone’s impatient and I can see why,” Jenkins said. “But there’s no easy path to this knowledge” about immunity.
Antibody tests differ from the standard nasal swab tests that diagnose active infections. Instead, they use blood to look for signs of a past infection, whether the person was sick or had no symptoms at all. Based on other viruses, experts expect those with coronavirus antibodies to be at least partly immune for several months.
Dr. Anthony Fauci and other members of the White House task force said early on it was a “reasonable assumption” that if “you have the antibody, you’re protected” but added therewasn’t proof.
To get that proof, scientists first run experiments in animals. Human trials come next and can take even longer. Researchers track people who had an infection and developed antibodies to see if they become reinfected. Their antibodies are measured to to gauge the level needed for immunity.
Jenkins and others said it’s possible that an effective vaccine will arrive before coronavirus antibody studies are completed. Vaccines spur the production of antibodies, and a number of coronavirus vaccines are now being tested around theworld.
In the meantime, experts say antibody tests are useful for two things: Large studies in the general population to see howwidely the coronavirus has spread, and screening people who may be able to donate their antibody-rich blood plasma, which is used as an experimental treatment for COVID-19.
But those uses were not the focus of White House briefings last spring, which attracted millions of cable TVviewers daily, according to Nielsen. A spokesperson for the White House coronavirus task force did not provide a response to requests for comment.
Expecting massive demand, the Food and Drug Administration chose a “flood-the-zone” strategy, allowing more than 170 tests to launch with little oversight.
At the same time, Trump highlighted his administration’s “fantastic progress” bringing antibody tests to market, some officialswere raising concerns. Reports of European governments forced to discard millions of faulty tests raised alarms.
The FDA pulled back on its lax policy for antibody tests in May, requiring companies to begin submitting data on accuracy. The FDA has authorized about 40 thus far, while dozens more await review.
But some testing companies continue to advertise the tests for workers and others. Big laboratories, including LabCorp and Quest, offer the tests to employers.
“We are aware of the CDC’s guidance,” Quest spokeswoman Kimberly Gorode said in a statement. “That is why we recommend that employers use antibody testing as part of a holistic approach to bringing their employees back to the office.”
LabCorp said in a statement: “As knowledge grows there may be benefit in having access to this information.”
The CDC and state public health agencies continue to use antibody testing to track the spread of the virus in the U.S. So far, in most areas studied, fewer than 5% of the population have antibodies — far below the levels that most experts think will be needed for herd immunity against coronavirus, underscoring the need for a vaccine.