The US Food & Drug Administration on May 8 gave emergency authorization to two COVID-19 test kits. The first of these uses CRISPR gene-editing technology to reduce testing cost and time. The second, which comprises a self-collection kit for saliva samples, allows people to take the test from the safety of their home.
The FDA gives emergency authorization when there is an urgent need for a test or therapy for which no approved alternative exists in the market. It is not the same as an FDA approval.
Also this week, Tata Sons signed a memorandum of understanding (MoU) with the makers of India's own CRISPR-based paper kit test, Feluda. The test, which costs about one-fourth of an RT-PCR test, is pending approval from the Indian Council of Medical Research (ICMR). RT-PCR is currently used in government and private labs to test for COVID-19. The ICMR has capped the pricing at Rs4,500 per test currently.
Sherlock CRISPR SARS-CoV-2 kit
US-based Sherlock Biosciences, along with researchers from the Massachusetts Institute of Technology (MIT) and Harvard University, has developed a COVID-19 test which can give results in an hour, compared with four to five hours for an RT-PCR test. It does this by looking for a specific signature of the COVID-19 virus, SARS-CoV-2. By contrast, RT-PCR is a painstaking and time-consuming task that looks for gene expression.
One of the co-founders of Sherlock, Feng Zhang, is also the co-inventor of CRISPR.
CRISPR, which stands for clustered regularly interspaced short palindromic repeats, is a gene-editing technology. Researchers can use it to edit sections of DNA. CRISPR slices the gene at the desired location following which changes to it can be made without altering the rest of the sequence. CRISPR can also be programmed to identify and isolate sections of genetic code, which is how it is being used in this case.
For now, only high tech labs will be able to make use of the test. The team has said that it is also working on a test that can be used by anyone and will not require sophisticated labs to validate the results. This easy to use, point of care test could play a key role in expanding diagnostic capacity during this public health facility. Using CRISPR technology could also make testing cheaper which would further expand access.
Feluda CRISPR-based test
Researchers at the Council of Scientific and Industrial Research's Institute of Genomics and Integrative Biology (IGIB), New Delhi, developed FNCAS9 Editor Linked Uniform Detection Assay or Feluda more than a month ago. The CRISPR-based COVID-19 test is called Feluda after the fictional detective in Satyajit Ray's novels.
Now, Tata Sons has signed a memorandum of understanding (MoU) for licensing of knowhow to make the kits. Regulatory authorization for this kit is currently pending. If this happens, Tata Sons said it would fast-track manufacturing to bring the kits to market in three or four weeks.
The IGIB researchers have said that Feluda can show results within 30 minutes and is four to five times cheaper than current RT-PCR tests. The test uses paper strips and looks similar to a pregnancy test. If the test is positive, a line will appear on the paper, and if it is negative, no line will be present. Unlike the RT-PCR test, his technology will not have to be done in labs.
Saliva self-collection kit
The second test to get US FDA authorisation on May 8 was developed by Rutgers Clinical Genomics Laboratory, at the New Jersey Medical School. The test comprises a self-collection kit that allows patients to collect, package and send their own saliva samples from home.
Staying at home right now is the safest option for the elderly, and for people living with diabetes, high blood pressure, cancer, asthma and a host of other chronic illnesses. Although these people are not necessarily at higher risk of getting COVID-19 infection, if and when they do contract it, they are more likely to get severely ill because of it than young and healthy people.
The kit could also reduce pressure on testing infrastructure and personnel, as people send in sealed samples from home rather than visiting testing facilities in person.
This test is currently only available in the US.