(CNN) Last March former President Donald Trump said "anybody that wants a test can get a test" for Covid-19. That wasn't true then, and in some parts of the country, finding a test appointment is about as easy to get as Super Bowl tickets.
Regular and affordable testing, if done right, could not only diagnose people who feel sick, it could stop the spread of the pandemic by letting people know if they are contagious and need to stay home, even if they don't feel sick.
Scientists have been pushing for this kind of testing -- accessible, affordable and ideally, at home -- since the start of the pandemic, but it hasn't happened yet.
There are at-home collection kits to make it easy for people to provide a sample, but the sample must still be sent to a lab, and results can take days. One over-the-counter, quick, at-home test has been authorized for use in the United States, but it's not available yet.
"Almost all the infections happen from people who don't know that they're positive, and so what you need is a widespread testing program that helps people identify when they are infectious so they can stop infecting other people," said Dr. Ashish Jha, a professor and dean at the School of Public Health at Brown University who wants more widespread testing. "We never really quite built that out."
Imagine being able to test yourself regularly before going to school or work, or before going to visit your elderly mom.
Jha said it works for his students and colleagues at Brown University. People there get tested twice a week. While there have been large outbreaks in Providence, where Brown is located, there have been almost no outbreaks on campus, even with a third of students living off campus.
"It was a great reminder that if you take a population of people, and do regular testing twice a week, that you can actually keep outbreaks under control," Jha said.
"If we could get some of these tests a bit more scaled up, we could use testing alone as a way to control the pandemic," Jha said.
So why hasn't it taken off?
Dr. Michael Mina, an assistant professor of epidemiology at the Harvard T.H. Chan School of Public Health, said the country hasn't scaled up the tests yet for a few reasons. One, the Trump administration "didn't want to see positive test results." While that's no longer a problem, he thinks, the "regulated environment" in the US would also need to change.
"We have the FDA that is kind of all controlling in some ways of what tests are available," Mina said. "The FDA, unfortunately, only has a single lens through which to look at a coronavirus test. Their only mandate, when it comes to testing, is to evaluate medical diagnostic tests."
He explains it this way: To be authorized by the FDA, a test needs to meet a certain sensitivity level. When a company submits its test for authorization, the test needs to be compared to another. In this case, the FDA requires that the comparison be what's known as a PCR test -- the most sensitive, gold-standard test for the novel coronavirus.
He thinks that standard is too strict and "that's what's slowing all of this down."
If you test a thousand people and you find a hundred are infected or PCR positive, Mina explains, it could be that 50 to 80% of them are no longer infectious, despite their positive results. An antigen, or rapid test is sensitive, but not necessarily sensitive enough to catch those people who were no longer infectious.
For surveillance testing, Mina says, your test only has to be sensitive enough to know if someone is infectious.
"We don't have the legal framework or the regulatory framework to think of a test in the United States as a public health tool, only as a medical diagnostic tool," Mina said.
The market is edging closer.
The FDA has already authorized more than 25 home tests, and that has sped up the process, but those tests don't provide rapid results. The swabs have to be sent off to a lab for evaluation. The tests also aren't cheap. They can cost $100 or more.
In December, the US Food and Drug Administration authorized the first antigen test you can use at home without a prescription that gives results in 15 minutes, the Ellume Covid-19 Home Test. It costs about $30. It's not available yet, but should be soon, the company said.
The country would need multiple rapid tests like that to help slow the pandemic and Mina thinks the tests should be subsidized by the government so they could test regularly.
"For less than .1% of what this virus is costing America, every American could have a whole slew of these tests in their homes," Mina said.
Rapid, inexpensive tests then could be another important tool used along with masks and vaccines to end the pandemic.
"If we actually got these tests into the average American's home and we asked every American to use a test twice a week, it takes 30 seconds to use -- as you brush your teeth, you use a Covid test -- that would be enough to empower people to know their status," Mina said. "And if they are positive, they would be able to essentially know that they're positive and make the appropriate changes."