The inventors of the FDA-authorized test are developing a simplified version they hope will eventually be approved for point-of-care or in-home 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 FDA-authoritzed test 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 Jonathan Gootenberg and Omar Abudayyeh hope the simplified CRISPR-based test, if approved, can eventually 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 authorization of the CRISPR-based test 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.”
The CRISPR researchers 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.
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.
This article has been updated to clarify the distinction between the FDA-authorized test and the simpler version under development.