Wanted: Rapid, Portable Tests for Coronavirus

At Brigham and Women's Hospital in Boston, a potential COVID-19 patient can now drive in to the ambulance bay, roll down their window, and ask staff to swab their nose and throat.

Those swabs will be sent to a state lab for a real-time PCR test, which amplifies any viral genetic material so it can be compared to the new coronavirus, SARS-CoV-2. But this standard test must be carried out in a certified laboratory with trained technicians, takes 3 to 4 days to deliver results, and produces some false negatives.

To speed and improve coronavirus testing, groups around the world are working to make rapid tests that can be done on-the-spot and diagnose the presence of the virus in just minutes.

Yet some companies have faced delays as they await government approval for testing or commercialization. On 29 February, the U.S. government finally released new rules that speed the approval process for new diagnostic tests, which may help the field move forward.

"The big benefit of our test over the traditional molecular PCR test is speed, and also that it can be deployed at point-of-care," says Kent Lupino, director of marketing at BioMedomics, which has a rapid COVID-19 test currently being used in China and Europe. The test detects the body's immune response to the virus from a few drops of blood in 15 minutes. The company is in the process of seeking approval from the U.S. Food and Drug Administration for emergency use.

Jiangsu Medomics, the China-based sister company of BioMedomics, has already sold nearly 500,000 of the rapid tests in China, where they are being used at doctor's offices, hospitals, and screening checkpoints, such as train stations and airports, says Lupino. The company does, however, recommend that a positive result from their rapid test be confirmed with a PCR test. BioMedomics currently has capacity to produce a million tests per week and could expand quickly, says Lupino.

Cambridge, Massachusetts-based biotech E25Bio already makes a rapid diagnostic test for dengue virus. Their technology relies on gold nanoparticles covered in specialized antibodies that hook onto parts of a virus or proteins secreted by a virus, producing a result in as little as five minutes, like a pregnancy test, says Irene Bosch, co-founder and CTO of E25Bio.

When coronavirus emerged, the company spent 23 days doing a high-throughput screen of their antibody library and produced several new antibodies based on the novel virus. "We were able to quickly iterate what we do in other viruses and apply our tech to SARS-CoV-2," says Bosch.

E25Bio now has all the components of their test ready for coronavirus diagnosis, but no access to the virus to test it. "The scientific community in Boston had not been cleared by the Department of Public Health in Massachusetts to open a vial of virus within secure facilities," says Bosch. She has been waiting two months for access to the virus, despite running a laboratory that already works with zika, dengue, and West Nile virus, among others. The company's manufacturer said they can shift from dengue to coronavirus and produce 100,000 coronavirus tests per day, says Bosch-once the test is ready. The Massachusetts Department of Public Health Bureau of Infectious Disease and Laboratory Sciences did not immediately respond to a request for comment.

At the University of Cincinnati, Chong Ahn and colleagues are adapting a smartphone-based rapid test for infectious diseases such as malaria. Their three-part design, published in January in the journal Microsystems & Nanoengineering, uses a custom, disposable plastic lab-on-a-chip; an optical detector that plugs into a smartphone and reads the chip; and a custom smartphone app that stores, analyzes and transmits the data.

With a single drop of blood or saliva on the chip, a smartphone will produce a result in 10 to 20 minutes, says Ahn, an electrical and biomedical engineer. His team is now adapting their platform to test for the presence of SARS-CoV-2 infection, but additional testing, clinical trials, and manufacturing could take six months to a year, he adds.

Rapid point-of-care testing will be critical for handling pandemic diseases like coronavirus now and in the future, says Ahn. In addition to detecting infections, such tests will also be valuable to measure the effectiveness of antiviral drugs and vaccines against the virus.