Scientists had cheap at-home coronavirus tests ready in 2020, but many still are not approved in the U.S.

In spring 2020, MIT scientist Dr. Irene Bosch helped develop rapid coronavirus tests. They were priced at $10, and with a factory ready to manufacture tests, they could scale up quickly. But the Food and Drug Administration never approved them.

Bosch's work was recently highlighted in a ProPublica investigation about FDA missteps regarding testing early in the COVID-19 pandemic. She joined Boston Public Radio to talk about missed opportunities for large-scale testing in the United States.

Before the pandemic, Bosch’s former company, E25Bio, worked to develop fast, inexpensive tests for tropical diseases. When the pandemic hit, she was able to quickly pivot to coronavirus tests, which she submitted for approval in late March 2020.

However, the FDA decided rapid, at-home tests needed to offer at least 90% sensitivity — meaning they could correctly identify nine out of ten positive samples — a very high bar that is difficult for at-home tests to meet.

“At that time, the FDA was so … careful and maybe thinking inside the box, and was unfortunately not experienced in controlling epidemics,” Bosch said.

Scientists like Bosch believe the sensitivity requirements should be lower, because PCR and at-home tests serve different purposes. Bosch says that while PCR tests work well for confirming if someone with symptoms is sick, they will not catch asymptomatic people who would not otherwise get tested without symptoms. In addition, PCR tests are difficult and costly to produce. With a large availability of cheap at-home tests, people would be able to monitor themselves on a regular basis, not just when they have symptoms.

“They [the FDA] didn't know that having a test such as the one we were making had a huge value, because you could do it anytime, anywhere, for anybody, so they couldn't really grasp the huge consequences of not allowing a test to be in the market really early,” Bosch said. “They did not have a concept of a monitoring test. All they knew was like ‘How good are you compared to PCR?’ It's just too short of a view on how you control an epidemic, because you have to be frequently testing the huge amounts of people who do not have symptoms.”

In 2021, the FDA lowered its threshold from 90% sensitivity to 80% sensitivity — a more realistic goal for at-home tests. Still, Bosch says the U.S. lags behind other countries with this type of testing.

“There's a huge disconnect to what the regulatory body did in Europe and Asia to what the USA does here, even today,” she said.

Now, Bosch is working to prove foreign tests’ efficacies in the U.S. Her latest project is a trial in Chelsea, which uses tests that are approved in other countries but not yet approved in the United States, and works with elderly, low-income residents to teach them how to use rapid tests at home.

Bosch hopes to see the FDA approve more tests so people can monitor themselves regularly. “There are hundreds of super good tests in Europe and Asia that could come today,” she said.

Dr. Irene Bosch is the founder of the diagnostic company E25Bio. She’s also a visiting professor at MIT, and adjunct professor of medicine at Mount Sinai University in New York.