This text is taken from the June 20 Coronavirus Courier, the last in the series. To subscribe to one of our newsletters, click here.
Despite thousands of scientific articles about it, the coronavirus responsible for COVID-19 still hides some secrets. What are they, starting with its trajectory this fall?
Two major uncertainties veil the future of the pandemic, according to Marc Brisson, a specialist in mathematical modeling related to infectious diseases at Laval University. “How long and how effectively can our immunity last? […] And what will the next variant look like? »
The risk of a new “Omicron-like” event, where the virus mutates enough to relaunch a large wave of contamination, is around 30%, according to experts. But this is only a theoretical estimate.
As for our collective immunity, acquired thanks to the vaccine and the infection, its level is considered “fairly good” by Quebec specialists.
But will this protection last until the return of viral diseases in the fall? Hard to say. The most vulnerable will undoubtedly play the role of the canary in the mine. “It will be necessary to monitor people aged 65 and over to ensure that the protection lasts over time,” notes Marc Brisson.
One of the certainties with COVID-19 is that we must expect surprises, evokes the professor from Laval University. “We learned one thing: if we had stayed with the original virus, we wouldn’t have any other waves. If we had stayed with the first variant, there wouldn’t have been any 5th or 6th waves. But, each time, we had a new variant that escaped immunity. »
The other uncertainty is when this new variant will appear. This summer, in the fall, or just before Christmas? “In my opinion, no one is able to predict it,” says Marc Brisson. “We have to remain vigilant. If mutations remain minor, with protection that persists, there is very little epidemic potential. »
The other mysteries
The famous “long COVID” is one of the other pandemic mysteries. The proportion of patients who suffer from symptoms for months varies, according to estimates, between 5% and 50%. Very few treatments exist for the moment against this evil which handicaps a large part of our societies.
Remedies have nevertheless progressed, with in particular the appearance of antivirals such as Paxlovid. “What is reassuring is that when the antiviral agents came out, the research did not stop,” underlines virologist Benoit Barbeau. Studies on “immunomodulators” promise in particular the discovery of treatments for vulnerable people.
Not to mention the future of vaccines, which looks promising. “We can hope that more local vaccines can be provided to us and will demonstrate effectiveness,” says Benoit Barbeau. “As for a universal vaccine [contre tous les coronavirus], it’s a wishful thinking, it’s not for tomorrow. »
The effects of COVID-19 in children also remain a great mystery. Both the ability of the youngest to resist the virus and the strange symptoms associated with childhood infection.
There is also, finally, the origin of the pandemic, which remains to be certified. It is highly likely that a zoonosis present in Wuhan triggered the crisis, but the WHO has recently revived the debate. Without identifying the “biological reservoir”, that is to say the band of animals carrying the original virus, it is impossible to cast the story in concrete.