President Trump at the White House on Monday announced a plan to distribute 150 million rapid coronavirus tests purchased by the federal government to states, tribes and other jurisdictions in the coming months.
Experts praised the news as a welcome endorsement of the importance of rapid and widely available testing while the nation continues to struggle in its fight to rein in the coronavirus, which has so far killed more than 204,000 people in the United States.
But the test numbers cited by federal officials, experts said, are nowhere what is needed to contain the spread of the virus.
“I’m happy that they are trying to invest in technologies that would expand the number of tests that could be done in the U.S.,” said Jennifer Nuzzo, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health. “That said, 150 million tests is really a very small drop in the bucket, considering how these tests are envisioned to be used.”
Since the pandemic’s early days, the country has struggled to get testing off the ground. More than 100 million coronavirus tests of various approaches have been conducted across the United States, with nearly 850,000 conducted each day.
But these numbers still fall short of the millions per day some experts say are needed to adequately assess the virus’s true prevalence in the population and help keep outbreaks in check. Long delays in returning results and supply shortages continue in many places.
Rapid tests, which don’t need to be routed through labs, have been proposed as an appealing alternative to fill that gap, especially if given frequently enough to catch infections early.
The tests that are to be distributed by the federal government, a product called BinaxNOW manufactured by Abbott Laboratories, do not require specialized equipment and can yield results within 15 minutes, based on a quick and relatively painless swab that shallowly samples the nostrils. Adm. Brett Giroir, a member of Mr. Trump’s coronavirus task force, demonstrated the administration of one of the credit-card-sized tests from a lectern in the Rose Garden.
Governors of some states, including New Jersey and Connecticut, announced on Twitter just before Mr. Trump’s news conference that they expected to receive thousands of the tests within coming weeks, and millions by year’s end.
Some 6.5 million of those tests would ship this week, said Admiral Giroir, adding that they could be used in settings such as doctor’s offices or pharmacies.
“This is, it was said by Republicans and Democrats alike earlier, this is a game changer,” Gov. Tate Reeves of Mississippi, a Republican, said at the White House news conference, adding that the kits would allow teachers in his state to be tested “every single day.”
The tests, which the Food and Drug Administration gave an emergency greenlight in August, are cleared only for use in people with symptoms of Covid-19 and must be administered by, or in the presence of, a trained health care professional. Such tests are intended for use, according to Abbott, within the first seven days of when a person starts to feel ill.
When the company sought approval, it did not demonstrate that its rapid tests were effective in people who don’t have symptoms, what is considered by the F.DA. to be an off-label use. But comments like Mr. Reeves’s suggested they might be used for screening or surveillance of people without symptoms in some locations.
“We don’t know anything about these tests’ efficacy in asymptomatic patients,” said Dr. Krutika Kuppalli, an infectious disease physician at the Medical University of South Carolina. “We need to be using tests that have been validated in their performance.”
The test is also designed to look for antigens, or pieces of coronavirus proteins. Such tests tend to be less accurate than laboratory tests, most of which rely on a time-intensive but very reliable technique called PCR.
Abbott has said that its test has been able to achieve results that mirror PCR testing more than 97 percent of the time in the lab. But the longer a person waits to be tested, the worse the Abbott technique performs.
Some have argued that frequent testing — perhaps on a weekly or even near-daily basis — could help compensate for the higher false negative rates of antigen tests. Such a feat, however, would require a far larger volume of tests than the amount laid out by the White House’s plans.
More than 50 million children are enrolled in public schools. Doled out to this population for daily testing, for example, about a third of the tests procured by the federal government would be depleted in a single day.
A number of experts have criticized a fast and frequent testing approach as logistically impractical, and worry that in certain populations where the virus is scarce, false positives could end up outnumbering true positives, compromising public trust in tests.
Mr. Trump said some of the tests would be distributed first to vulnerable populations. Among these groups will be those living in nursing homes and assisted living facilities, as well as those at historically Black colleges and universities and tribal nation colleges. Black, Latino, Native and Indigenous people have been disproportionately affected by the coronavirus.
But Howard Koh, a public health expert at Harvard University, said there had been no clear guidance on how the results of tests performed outside the health care system would be reported to officials trying to track the virus’s spread. Schools in particular might not have the capacity to track such data.
“Having the tests available is positive, but we need to have a better system,” Dr. Koh said.
Earlier on Monday, the World Health Organization announced a global partnership to make 120 million rapid coronavirus tests available to low- and middle-income countries, including a $50 million commitment from the Global Fund.
“We’re finally seeing better testing out there,” Dr. Kuppalli said. “But we need to be rolling it out in a way that is mindful that it’s being used appropriately.”