Here we go again: FDA opens up emergency authorizations to monkeypox tests

Using what was once a lesser-known regulatory option made world-famous by the COVID-19 pandemic, the FDA has granted its first Emergency Use Authorization to a diagnostic test for monkeypox as cases continue to spread worldwide.

This category of green light is aimed at speeding products to market during a public health emergency—which the U.S. Department of Health and Human Services declared for monkeypox in early August—and allows the FDA to authorize unapproved uses when there are no available alternatives.

The agency issued an emergency authorization last month for Bavarian Nordic’s Jynneos vaccine. Though first approved for smallpox and monkeypox in 2019, the latest EUA enabled the shot to be given in smaller doses, in a bid to stretch out supplies. According to an HHS release this week, the government has made nearly 1.1 million vials of the vaccine available to order and has shipped more than 772,000 vials so far.

Now, the FDA has granted its first emergency diagnostic green light to an automated PCR test developed by Quest Diagnostics that analyzes swabs taken from skin lesions suspected to be caused by the monkeypox virus.

According to a release from Quest, the diagnostic was first launched this summer as a lab-developed test, and samples will be processed at laboratories in California and Virginia as the company prepares to supply healthcare providers on both coasts of the country. Quest previously said it expects to be able to perform at least 30,000 tests a week, depending on demand.

In addition, the test was designed to detect two different DNA targets related to monkeypox and the closely related non-variola orthopoxvirus to help protect against false negatives and a rare genetic mutation that could occur in a future disease variant, according to Quest.

At the same time, the FDA said it does not plan to enforce certain federal regulatory requirements for monkeypox tests developed by laboratories and used without an emergency authorization. The agency instead requests that tests be “appropriately validated” and that the laboratories notify the FDA of their use within 30 days.

In its guidance (PDF), the FDA said it plans to prioritize EUA reviews for high-throughput diagnostics, tests where the sample can be collected at home, or rapid antigen tests, all from “experienced developers with high manufacturing capacity.” These companies must also tell the FDA they plan to submit a future EUA request within 30 days of notifying the agency their test is available.

“The agency’s intent is to facilitate the development of additional tests to address local availability and accessibility concerns not addressed by current testing capabilities,” the FDA said in its release. “The FDA will monitor the situation and may adjust its policies as appropriate to address testing needs.” 

The policy is somewhat reminiscent of actions taken in the earliest stages of the coronavirus pandemic, where certain tests were allowed to enter the market without first completing FDA review and obtaining federal permission.

Dozens of COVID antibody blood tests, for example, were allowed to be sold and shipped as long as they carried certain buyer-beware caveats, while the agency instead focused on processing a deluge of applications for new molecular diagnostics for detecting active coronavirus infections. 

This allowed large shipments of tests of dubious quality and accuracy produced by overseas manufacturers to enter the U.S. market—including some products that were outright fakes

The FDA would later reverse course, order tests to be taken off the market and said its experiment in “regulatory flexibility” should not have allowed fraud. Ultimately the agency nixed listings for 225 tests from its website, issued at least 15 warning letters and placed import alerts on 88 companies that allowed their shipments to be seized at the border.

Nearly a year later, agency leadership described those policies as flawed, in hindsight. 

The FDA’s device center director, Jeff Shuren, and the agency’s in vitro diagnostics chief, Timothy Stenzel, wrote a February 2021 editorial published in The New England Journal of Medicine. 

“Knowing what we know now, we would not have permitted serology tests to be marketed without FDA review and authorization, even within the limits we initially imposed,” they wrote. “Although other factors may have driven unauthorized products to flood the marketplace, our March 16 [2020] policy allowed it to happen.”

The FDA would go on to work directly with the National Institutes of Health, the National Cancer Institute, the Biomedical Advanced Research Development Authority and the CDC to appraise the accuracy of antibody tests themselves.

This time around, the FDA appears to be narrowing the scope of unreviewed serology tests used to track antibodies related to monkeypox infections. 

The agency said it does not plan to object to the use of antibody tests developed and performed by CLIA-certified laboratories operating under academic medical centers, where test results will be used alongside other diagnostics for the direct medical care of a patient. 

“This should mitigate the potential misuse of monkeypox serology test results while also fostering research from availability of data from serology testing of patients,” the FDA said. “For example, these laboratories can test their patients daily or frequently over a period of time to monitor immune response and are most likely to benefit from the information learned from serology testing at this stage of the monkeypox outbreak.”

As of Sept. 7, more than 21,200 monkeypox cases have been confirmed within the U.S., according to the CDC.