A first launch for EasyCov
On November 28, the French High Authority for Health issued a positive opinion on the use and reimbursement of the rapid SARS-CoV-2 detection test developed by the Montpellier-based joint laboratory (CNRS/Alcen) Sys2Diag. Use of the test is currently subject to conditions: only symptomatic patients for whom nasopharyngeal swabbing is impossible or difficult are eligible. And any positive result must be confirmed by a conventional PCR test. Mixed reactions from its designers...
Concerned about a possible SARS-CoV-2 infection? It would be so easy if you could simply take a saliva sample and get the test results in just 40 minutes. Such a test exists, and it's called EasyCov. Hundreds of thousands of units have been sold abroad for several months now... but not in France. Ironically, however, it was in Montpellier that this device was designed. Certified with the "European conformity" mark last June, its rollout in France has so far been suspended pending the opinion of the Haute Autorité de Santé (HAS).
Limited use by the HAS
Interviewed on November 26, the day the HAS verdict was expected, Franck Molina, a CNRS researcher at Sys2Diag, was certainly impatient but confident: "The clinical study conducted with the university hospital is unequivocal and shows the extremely good performance of the test. The High Authority is doing a remarkable job, but we would have liked to deploy it earlier to deal with the second wave."
On November 28, however, scientists in Montpellier expressed more nuanced satisfaction. Although the HAS has issued a positive opinion on the use and reimbursementof EasyCov, "which is already a major step forward," says Franck Molina, it limits its use to symptomatic patients for whom nasopharyngeal swabbing is impossible or difficult to perform, and requires a follow-up RT-PCR test in the event of a positive result. This restriction therefore reduces the appeal of this rapid saliva test for the time being, "but we are already working with the HAS to expand its use," the researcher continues.
40 minutes from sample collection to diagnosis...
EasyCov is a PCR test similar to the conventional tests currently in use, known as RT-PCR, but it differs radically from them thanks to a technology called LAMP-PCR, which offers numerous advantages. First of all, the sample is taken from saliva rather than the nasopharynx. "It's a self-administered test, which is simpler and well accepted by the public. The test can be performed as many times as desired, which makes life easier for healthcare workers," explains Franck Molina.
The analysis is also greatly simplified. There is no longer any need for laboratories or machines; the virus extraction and purification steps required for amplification in the RT-PCR technique are replaced here by simple heating. "The analysis is carried out in two stages: heating to 80°C for ten minutes and then to 65°C for 30 minutes, which allows the virus to be amplified using LAMP technology. The test consumes very few enzymes and almost none of the products that are so difficult to find in times of crisis," continues the researcher. Few products are required, resulting in a very low cost price.
Finally, the diagnosis is delivered immediately via an application developed in partnership with Montpellier-based company Vogo. "The application provides a real-time diagnosis using a colorimetry system: yellow for positive, orange brick for negative. The result is immediately transmitted to the relevant authority: ARS, doctor, airport authority, medical staff of a sports club, etc.," concludes Franck Molina. And here again, the time savings for healthcare personnel are considerable.
One study but two different interpretations
The EasyCov test therefore ticks all the boxes in terms of addressing the problems encountered in this global crisis, such as product availability, large-scale development with good social acceptability, and a relatively low cost to society. Better still, it is also more reliable than conventional RT-PCR, according to a clinical study conducted by Professor Jacques Reynes' team at Montpellier University Hospital on more than 500 patients, including 450 drive-through patients in real-life situations. "It's interesting because we tested it in real life. These patients were tested with the EasyCov saliva test and with the RT-PCR technique on nasopharyngeal and saliva samples," explains Franck Molina.
And the results are unequivocal for the Montpellier researchers, who claim that "the EasyCov test detects 88% of infected patients, compared to less than 70% for the nasopharyngeal RT-PCR test. It has a specificity of over 99%, meaning less than 1% false positives." And that's where the problem lies. Based on the same study, the HAS concludes that the specificity is 92%.
Why such a difference? Because the HAS considers that only the nasopharyngeal PCR test is reliable. In other words, if a patient tests positive on the EasyCov test and the saliva RT-PCR laboratory test but negative on the nasopharyngeal RT-PCR test, it considers that the first two results are false positives, resulting in a lower specificity rate.
A collective adventure in Montpellier
While awaiting further guidance, Franck Molina's team continues to move forward in consultation with the HAS. The researcher remains positive: "Under normal circumstances, it would have taken several years to develop and market such a test. We worked seven days a week, almost 24 hours a day, to save time and respond to the emergency." All this took place in a difficult context due to the first lockdown, which nevertheless did not prevent many players from responding to the call from the Sys2Diag laboratory. Public partners such as the infectious diseases department at Montpellier University Hospital,the Montpellier Institute for Infectious Disease Research (IRIM) located on the CNRS site, the UM's DNA and oligonucleotide synthesis platform, and Monsef Benkirane's team atthe Institute of Human Genetics (IGH). But also private companies such as Vogo and numerous local and regional laboratories. "It's not just Sys2Diag, it's a Montpellier operation. We have been through a human adventure that we hope never to experience again, but which has left its mark on us both individually and collectively," concludes Franck Molina. An adventure that has been recognized with the MUSE innovation award.