EXCLUSIVE: a new single-use Covid-19 test offers hope for economy while waiting for a vaccine

I joined him that day to visit Click Diagnostics, a start-up from Silicon Valley backed by venture capital firm NanoDimension, which he has since joined.

We hadn’t even left the parking lot when Aebischer began enthusing about the start-up’s latest innovation. Click had managed to miniaturize a polymerase chain reaction (PCR) diagnostic test into a disposable device the size of a matchbox. The result was an individual molecular diagnosis as fast and as simple as a pregnancy test.

Today, PCR tests have entered everyday discourse because of the Covid-19 pandemic. In essence, it is a matter of amplifying the genetic material of a cell, bacterium, or virus such as SARSCov-2 to make it detectable even if there is very little present in a sample taken from a patient. To do this, large machines carry out these tests in batches. The disadvantage is that a large number of samples must be collected before starting a test cycle

At the beginning of July, Patrick Aebischer showed me the first prototype of a miniaturized PCR test developed by Click, which has since been renamed Visby Medical, to detect Covid-19: the first personal diagnosis of this economically crippling disease. All you have to do is take a sample from the nose, place it in a small receptacle, and press two buttons to get the result, Covid-19 or not. The question is, will this be a "game-changer"?

Let's just say that it may be part of the solution while waiting for an effective vaccine. I remembered this prototype when I read an article published by the Harvard Business Review last week. Michal Mina, a professor of epidemiology at Harvard University's T.H. Chan School of Public Health, advocated a new screening strategy that tests everyone with individual rapid devices so that people infected by the disease can be easily identified and then isolated to nip the chains of transmission in the bud. To do this, Michael Mina recommends the use of lower-cost paper-based serological tests.

When a person is infected for the first time, there is an incubation period during which no test reveals the infection because the viral loads are too low. Three to five days later, PCR tests become positive as the virus replicates exponentially (10,000 to one million new viruses are produced for each infected cell).

Rapid tests do not detect the virus but the presence of antibodies generated by the immune system. They are able to do this from about seven days after infection, which is not too long after PCR test. Developed by an army of start-ups such as Sherlock Biosciences, a spin-off from Harvard's Wyss Institute for Biologically Inspired Engineering, these tests exist. But in the United States, they have not yet been approved by the health authority (FDA) for marketing because they are less reliable than PCR tests. In Europe, the CE mark authorizes its sale. But it is not recommended by health authorities for the same reasons.

Michael Mina argues that the unreliability of these paper serological tests does not pose a serious problem because the frequency of screening - every two days, he says - would statistically reduce the risk of error. Above all, because this strategy must be compared to the current situation. Today, the average response time for a person doing a Covid-19 PCR test in the United States is 6 days. This means that this person waiting for a result has plenty of time to infect others and plenty of time to catch it if this was not the case at the time of the test. Michael Mina believes that testing everyone with imperfect serological tests will still give us a much more accurate picture of the epidemic, and that with targeted quarantines of those who test positive, we will be able to contain it.

This plan, however, comes up against several difficulties. Who will reimburse or pay for these tests, which, even if cheap, would be used on an unprecedented scale? Then, when we see the polemics over masks, we remain doubtful about the adoption by the population of such frequent tests, especially in Europe where for the moment the epidemic rebound remains under control.

On the other hand, one cannot exclude a winter wave complicated by the flu or even simple colds and their abundant dispersions of droplets potentially carrying the virus (one can perfectly well sneeze with a bad cold while being an asymptomatic carrier of Covid-19). In the absence of a vaccine for everyone this winter, which is likely, will the authorities have no choice but to impose new confinement measures, this time fatal to the economy? No, thank you.

This is where Visby Medical's PCR test comes in. Contacted by Zoom, the company's founder, Adam de la Zerda, does not think that the device, which is now in the final stages of evaluation by the FDA, will be designed to test everyone all the time. It will be significantly more expensive than a paper test. And even though it is as reliable as the mass PCR tests used by labs, it is not intended to replace them, although it delivers its diagnosis in 25 minutes versus 4 to 5 hours.

On the other hand, it could be used as an intermediate device to contain the epidemic, particularly by protecting those most at risk. This is central since it is this protection that justified the extreme measures taken last spring.

What Adam de la Zerda proposes is to use this technology to create "coronavirus-free" zones around the most sensitive areas: EMS, treatment centers for cancer patients or dialysis centers for diabetics, etc. Equipping these places with large PCR machines seems indeed difficult given the capital investment it would require, with instruments designed not to perform a targeted test on demand but hundreds of them in parallel. A single-use personal test such as the one developed by Visby would be much more reliable than temperature taking. It would also offer a much better solution than having to confine an entire nursing home to a room after having to test all the staff and residents at each alert and while waiting for the results.

The next question is an economic one. How much for this individual test? The price has not been disclosed but should be much cheaper than having to test an entire retirement home (or any other potential communities at risk). And it would also be infinitely cheaper than a what a second lockdown would cost the economy due to a resurgence in Covid-19 cases.