The inevitable end to a hasty emergency decision with easily predictable consequences. After watching a flood of “unscrupulous actors marketing fraudulent test kits,” the Food and Drug Administration today reversed its earlier decision on experimental antibody test kits. From now on, only those tests that have been granted emergency use authorization can be sold in the US, reducing the market down to a dozen products:

U.S. regulators Monday pulled back a decision that allowed scores of coronavirus blood tests to hit the market without first providing proof that they worked.

The Food and Drug Administration said it took the action because some sellers have made false claims about the tests and their accuracy. Companies will now have to show their tests work or risk having them pulled from the market.

Under pressure to increase testing options, the FDA in March essentially allowed companies to begin selling tests as long as they notified the agency of their plans and provided disclaimers, including that they were not FDA approved. The policy was intended to allow “flexibility” needed to quickly ramp up production, officials said.

“However, flexibility never meant we would allow fraud,” Dr. Anand Shah, an FDA deputy commissioner, said in a statement. “We unfortunately see unscrupulous actors marketing fraudulent test kits and using the pandemic as an opportunity to take advantage of Americans.”

Fraud? In medical quasi-scientific consumer products? The deuce you say. The FDA has an entire section of its website dedicated to warning against false and/or unproven claims from over-the-counter products, which sell like hotcakes to people worried about their health even under normal circumstances. Removing all restrictions in a global pandemic? Fuhgeddaboudit.

The FDA had its heart in the right place by allowing test manufacturers to flood the zone with new capacity to identify COVID-19 antibodies as a way to leverage private-sector innovation. Unfortunately, the lack of solid science behind the tests — and the desire to sell them under any pretenses necessary — made the flood of new tests more dangerous than the lack of reliable tests. False positives on antibody tests would encourage more public circulation of people who unknowingly remain vulnerable to a COVID-19 infection. Thanks to the asymptomatic contagious period, bad tests would also allow those people to amplify the spread of the disease at some point as well.

This move was overdue, as these issues had been emerging for weeks. One major issue is that the better tests might have suffered from the lack of confidence that had developed over antibody testing with the fraudsters still in the market. (My clinic issued a warning to its patients not to seek any antibody testing at all until the FDA took more action, for instance.) The good news is that the FDA is still adding new tests to its officially authorized list, including a new antibody test from Roche today. The data from Roche promises a 99.8% accuracy rating, but this still requires a clinic visit and a full blood draw despite the stock video Today uses to highlight the news:

Basel-based Roche, which also makes molecular tests to identify active COVID-19 infections, said its antibody test has a specificity rate exceeding 99.8% and sensitivity of 100%, meaning tests would show very few false positives and no false negatives.

A false-positive result could lead to the mistaken conclusion that someone has immunity. Roche said its test relies on intravenous blood draws, with higher accuracy than finger-prick tests.

“If you take blood from a finger prick, you will never be able to achieve the same level of specificity that you will achieve … when you take blood from the vein,” Schinecker said.

“You have to have very, very high specificity. Even 0.1% or 0.2% makes a difference.”

Once we have firmly established that antibodies indicate a resistance to infection, these tests will have a critical impact on our ability to re-enter normal economic activity. Shelter-in-place isn’t sustainable and isn’t working as well as people had hoped, former FDA chief Scott Gottlieb told CNBC’s Squawk Box. To get to a point where we can live with COVID-19, we have to get people vaccinated and increase herd immunity. More than anything, though, we need reliable tests and vaccines, not snake oil — a point that the FDA belatedly embraced today.