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An Epidemiologist Says At-Home Testing Is Key To Stopping COVID

At-home tests are becoming increasingly difficult to find despite manufacturers boosting production as COVID-19 cases rise in schools and employers increase monitoring.
Scott Olson
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At-home tests are becoming increasingly difficult to find despite manufacturers boosting production as COVID-19 cases rise in schools and employers increase monitoring.

The COVID-19 response plan that President Biden unveiled last week aims to dramatically increase the accessibility of rapid tests for the coronavirus.

The Biden administration announced it was spending $2 billion on 280 million quick-turnaround tests to be distributed to community health centers, food banks, testing sites, shelters, prisons and other congregate settings. It's also leaning on Walmart, Amazon and Kroger to sell rapid tests at wholesale cost for the next three months.

Such quick-turnaround tests can be taken at home or at a point of care and deliver results often in under an hour — as opposed to the more sensitive but more time-consuming PCR tests that require laboratory processing.

Dr. Michael Mina, an epidemiology professor at the Harvard T.H. Chan School of Public Health, has been an outspoken proponent for wide availability of rapid tests, even with the arrival of effective vaccines.

"Should anything go wrong with the vaccines, we need backup plans," he told NPR's Mary Louise Kelly in April, before the highly contagious delta variant drove the current wave of infections. "If new variants come around that get around people's immune systems, especially in elderly whose immune systems a year after they get vaccinated might be waning in terms of their level of protection, we want to be able to limit spread as much as possible."

In a new conversation with Kelly on All Things Considered, Mina warned that even with increased production, the availability of tests will soon become an issue after Biden announced that businesses with 100 or more employees must either require their employees to be vaccinated or test them weekly.

There are already reports of these rapid at-home antigen tests being hard to find on store shelves and online.

"We are about to see what I think is going to be another testing crisis in this country," Mina said. "While I am extraordinarily supportive of the president's action plan to increase the accessibility and availability of these rapid tests ... unfortunately, we do not have the scale of either [rapid or PCR] tests to be able to get fast turnaround time."

Interview highlights contain extended web-only sections.

Interview Highlights

On how well rapid antigen tests work compared to PCR tests

For public health, [rapid tests] work very well. And what I mean by that is if the question is "Am I infectious right now?" then these tests are very accurate. They have very high sensitivity to detect people who are currently infectious. The PCR test is the gold standard, but as a medical diagnostic. If as a physician, a patient says, "I want to know 'was I infectious last week?' " the PCR test can help with that. But the delays and the lack of ready access makes [PCR tests] a much more ill-equipped test to be able to actually curb spread during this pandemic.

On why businesses, schools and other institutions do not accept rapid tests

In the United States, we have had this unfortunate misperception that has really started with the federal government in 2020 ... that these tests were not accurate. ... A lot of our research at Harvard was dedicated this past year just to show that we need to hold public health tools to a different set of standards. Not worse, but different.

And that it's actually the speed of a test and not just the molecular sensitivity that becomes much more crucial. ... These tests are the absolute better test for public health. And now finally, we are seeing the CDC recognize this. We're in fact, of course, seeing the Biden administration recognizing this.

On whether he would rely on a rapid test for his child

The short answer is yes, I would rely on it. But if there are outbreaks in my community going on and my child has COVID symptoms, then in this climate I would not send my child to school if they had symptoms, and that should be step one. ...

And the reason is there isn't another choice. You can say I want a PCR test, but you're not going to get that result for three or four days. By the time you decide to make an appointment, get the swab, send it out to a lab, get the results two days later. So there isn't actually a better option for the immediate term. And so as a parent, I would say, yes, absolutely. This is the best test I have at my disposal right now.

And even if somebody is symptomatic, if they are not turning positive on a rapid test, they are very, very unlikely to be spreading the virus. The symptoms are often the immune response to the virus, so they might have been infectious two days ago, but if they're negative now, they're probably not transmitting now.

On why rapid testing still costs so much in the U.S.

The United States is a major outlier in this way. Around the world, if you go to Europe, you can you can get these tests for under a dollar, and you can in fact get them all the time. They're available; they're readily available anywhere. You could go to the U.K. and you can get seven tests for free, delivered to your door every single day, if you want.

The reason it's so expensive here is because we have no market competition. ... The actual cost of the devices is very inexpensive. But what we need is market competition. We need more producers to get into the United States market. And to do that, we have to release some of the regulatory barriers that we have thus far had.

On whether President Biden's new rapid test initiative will get the U.S. enough testing kits

So the Biden plan at the moment — and I want to be very clear about this — will not get the U.S. the number of tests that we actually need so that people can feel confident that when they walk into their CVS that they will see a box of rapid tests that are available. But what the Biden plan is doing is it will stimulate an increase and flurry of activity from companies to try to sell their tests in the U.S. market. Because now we have for the first time, very wide and high level support for these tools. So it will stimulate U.S. innovation and foreign innovation — and these companies actually exist. We could have tens of millions of tests every day available on the shelves instead of 1 million if we allow increased companies to enter into the market. And I think the Biden plan is going to very much stimulate that.

On how the federal government could make rapid testing cheaper and even more widely available

The president can come out and state that testing for public health during a public health emergency is utilizing public health tests and tools and not medical devices. And why that's so important is: If we define these tests as public health tools, then we can use a whole different set of regulatory metrics to evaluate and authorize them very, very fast. And it would allow us to very quickly catch up to our European peers. So it's actually just a simple problem of how we define these tests in the United States versus Europe that is really preventing them from coming to the U.S. market.

So the president has a solution. There is a simple solution. We just have to make sure that everyone is aware of what the real bottleneck is here.

Sam Gringlas and Sarah Handel produced and edited this conversation for broadcast. Patrick Jarenwattananon adapted it for the web.

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Mary Louise Kelly is a co-host of All Things Considered, NPR's award-winning afternoon newsmagazine.