WASHINGTON – The Food and Drug Administration on Thursday (May 7, 2020) approved a new diagnostic tool that employs the revolutionary CRISPR gene-editing technology to determine in just one hour if someone is infected with the novel coronavirus.
The FDA’s emergency use authorization allows only “high-complexity” laboratories to use the test kit, developed by researchers at the Massachusetts Institute of Technology, Harvard University, the Ragon Institute and the Howard Hughes Medical Institute and marketed by Sherlock Biosciences of Cambridge, Mass. The inventors and marketers of the test describe it as highly accurate and easy to use.
“We think this has a lot of potential. The test doesn’t require any complicated or expensive equipment,” said Feng Zhang, a leader of the research team.
Zhang, an internationally renowned molecular biologist, is affiliated with the Broad Institute and the McGovern Institute at MIT and is a co-founder of Sherlock Biosciences. He’s a co-inventor of CRISPR, a gene-editing system that exploits a natural immune response system used by bacteria to fight off viruses.
CRISPR – for Clustered Regularly Interspaced Short Palindromic Repeats – is not the first or only technology for manipulating genes, but it is prized for its relative simplicity and versatility. It has also generated soul-searching and protracted debate in the scientific community because of potential misapplications of the technology.
Sherlock Biosciences said the kit works by using a CRISPR-engineered molecule to detect the genetic signature of the SARS-CoV-2 virus. When the signature is located, the company explained in a news release, “the CRISPR enzyme is activated and releases a detectable signal.”
Zhang and his colleagues have yet to gain approval for point-of-care use of the new test kit. They hope it eventually can be widely distributed and used even by nonprofessionals for rapid diagnosis. For example, it could be deployed in an office building to screen employees, Zhang said.
“You can imagine a makeshift lab in a nursing home or an office or a drive-through testing station,” he said.
The FDA issues emergency use authorizations for deployment of unapproved medical products on a temporary basis during public health emergencies. In the current pandemic, the agency has granted hundreds of authorizations, including for diagnostic tests to detect the virus; antibody tests to check whether a person has been exposed to the virus and developed antibodies; medical devices such as swabs and ventilators; and for an antiviral drug called remdesivir from Gilead Sciences.
The new CRISPR-based test has already been rolled out in Thailand, using an earlier formulation. The authorization for use in the United States comes as testing for the coronavirus has improved but remains far short of what public health officials desire. They say many states and localities still are not doing enough testing, in part because of shortages of important chemicals, laboratory staff and equipment.
“We want the quickest diagnosis, closest to the patient,” said Scott Becker, chief executive of the Association of Public Health Laboratories. “Right now, there’s limited point-of-care [testing], and anything to expand lab capacity that’s good quality testing is going to be welcome.”
He added: “There has to be availability of the test. I don’t want a new test out on the market that’s only going to cover 1,000 people a day.”
Sherlock Biosciences, founded only a year ago, was already working on a diagnostic test kit for dengue and Zika, two other infectious diseases, when the coronavirus outbreak began late last year in China. The company realized the technology could be deployed to combat the new virus and would be particularly helpful in places with limited laboratory equipment or medical infrastructure, such as in the developing world.
Jonathan Gootenberg, one of the inventors, said the researchers asked themselves, “How do we make the simplest test possible – something that could be done at point-of-care, as we say – without any complex equipment or experimental procedures?”
They are trying to prove that the technology could be used not only on samples from the upper respiratory tract and the lungs but also on saliva. That would potentially make the test less invasive and uncomfortable than the nasal swabs used in the most common tests.