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The public must exercise caution when using coronavirus blood tests as many are unregulated, health officials warn.

As part of its emergency response to the pandemic, the Food and Drug Administration waived an initial review of blood tests. More than 70 companies have signed up to sell so-called antibody tests, but questions remain as to their accuracy.

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“Right now it’s a wild West show out there,” said Eric Blank of the Association for Public Health Laboratories. “It really has created a mess that’s going to take a while to clean up.”

“In the meantime, you’ve got a lot of companies marketing a lot of stuff and nobody has any idea of how good it is,” he said.

Blood tests are different from the nasal swab-based tests currently used to diagnose active infections, instead identifying antibodies found in blood proteins. The approach is used to identify diseases such as HIV, hepatitis, Lyme disease and many others.

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“Some firms are falsely claiming that their serological tests are FDA approved or authorized, or falsely claiming that they can diagnose COVID-19," Dr. Stephen Hahn of the FDA said in a press release. "The FDA will take appropriate action against firms making false claims or marketing tests that are not accurate and reliable.”

Hahn confirmed that the FDA has authorized one blood test for use in clinical labs.

Dr. Allison Rakeman of NYC’s Public Health Laboratory explains that faulty tests might cause people to mistakenly believe they are immune or no longer spreading the virus.

“Then somebody goes home and kisses their 90-year-old grandmother,” said Rakeman. “You don’t want to give someone a false sense of security.”

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Medical experts have no consensus as to what percentage of coronavirus carriers are asymptomatic, with estimates ranging between 25 to 50 percent.

Officials in Laredo, Texas, reported this month that some 2,500 antibody tests set for use at a local drive-thru testing site were likely frauds. City officials had ordered what they were told were “FDA-approved COVID-19 rapid tests” from a local clinic, but later found the test’s accuracy fell well below the range promised.

“If you see them on the Internet, do not buy them until we can give you a test that’s reliable for all Americans,” said Dr. Deborah Birx, coordinator of the White House coronavirus task force, at a recent briefing.

Companies are working to rush out appropriate tests, but they face plenty of "red tape" in getting the proper approval.

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Dr. Stephen McColgan, chief medical officer at California-based Vivera Pharmaceuticals, told "Tucker Carlson Tonight" Wednesday that his company's rapid antibody test has been ready for three weeks.

"You know, the red tape in the FDA and President Trump has been trying to cut through it," McColgan said. "You know, it's always sort of the red tape of government moves slowly."

The Associated Press contributed to this report.