The government’s stopgap test for the new coronavirus has prevented the United States from doing the kind of rapid diagnosis and monitoring that experts say is essential to minimize a disease’s spread.
But that should change within a few months, as dozens of leading diagnostics companies are racing to get emergency permission to roll out automated molecular tests.
At the front of the pack is California-based Cepheid. It is in the final phases of developing a cartridge designed to work on its automated system. That system is already in use in 23,000 hospitals, clinics, and other locations worldwide, and is expected to provide coronavirus results in about 30 minutes.
Cepheid is asking the U.S. Food and Drug Administration for “emergency use authorization” so it can launch the test in the second quarter of this year, April through June. "We’re hoping for earlier rather than later in Q2,” said chief medical and technology officer David Persing.
Michael Mina, an epidemiologist and immunologist at Harvard University’s School of Public Health, said he had talked to several other companies that are also close to having a test that could be used on a large scale.
“It will be mid-April — possibly mid-March — given the speed and the massive interest because of the very limited U.S. testing capacity," Mina said.
Another company in the race, Switzerland-based Roche, would not discuss timelines, but said the company’s emergency response team was working on a test that would plug into its widely used diagnostics platform.
Emergency use authorization, which allows unapproved medical products to fill a critical public health need, was previously granted to the U.S. Centers for Disease Control and Prevention for the coronavirus test kit it hastily created in January. The kit is laborious and takes at least a day to yield results. It also had a faulty component when it was distributed to state labs — although the CDC said Friday that the problem has been resolved and states can begin testing.
The urgency is growing as coronavirus outbreaks explode around the globe, stock markets plunge, and deaths counts climb. As of Friday, there were more than 84,000 confirmed coronavirus cases and 2,800 deaths, according to the World Health Organization. Most are in China, where the virus emerged in December, but 56 other countries — and more every day — have reported cases.
While China, South Korea, and other countries are assessing vast numbers of samples with their tests, only about 500 people in the U.S. have been tested for the virus, called COVID-19. Experts worry that the 60 U.S. cases confirmed so far do not reflect the real prevalence of the germ — especially now that cases with no known source of infection suggest the virus is spreading from person to person in California, Oregon and Washington.
That case prompted the CDC on Thursday to broaden its narrow testing recommendations. Now, testing should be done for anyone with respiratory symptoms and a history of travel to an affected country — not just China — or anyone with severe respiratory illness that has no alternative explanation.
Although the CDC’s test is still the only authorized option, an FDA spokesperson said it is cooperating with more than 70 molecular diagnostics developers, such as Cepheid, "to help accelerate” emergency approval of a commercial test.
All of these candidates use PCR (polymerase chain reaction), a Nobel Prize-winning technology that has revolutionized molecular biology since its invention in 1986. It creates millions or billions of copies of DNA using an original strand from a sample of blood or other body fluid. PCR is so sensitive that it can detect a viral infection even before it causes symptoms. PCR is now used to diagnose Ebola, flu, tuberculosis, and many other diseases.
“PCR is well-established technology, and many companies have automated versions,” Cepheid’s Persing said. “An assay can be developed in the lab in a matter of days if you have the DNA sequence. China has been very forthcoming” with viral genome data.
That doesn’t mean PCR is simple. One of the challenges involves the fact that viruses are constantly mutating — altering their genome. A test won’t work if it’s designed to detect and copy a DNA sequence that no longer exists. That’s why Cepheid’s test targets three regions of the coronavirus genome.
“We’re future-proofing the test," Persing said. “That’s what we’re striving to do.”