Several viral loads are currently jostling at the gate to infect our respiratory tract. Will they keep Covid-19 at bay or will they have to share their guests? Two scenarios, two different outcomes.
With the lack of hindsight, some had imagined that the virulence of SARS-CoV-2, responsible for the Covid-19 pandemic, would decrease as temperatures warmed . It is clear that the virus continues to rage at a very sustained pace. To date, more than 19.6 million people have been infected worldwide since the end of December, according to a count carried out on Sunday August 9 by Agence France-Presse (AFP). Of this sample, nearly 730,000 of them were killed.
Another question now arises, as autumn, and especially winter, looms:how will SARS-CoV-2 react in contact with other loads? viral?
No need to hide your face, the new coronavirus will still be here in October , as it will still be there at Christmas and next spring. Until then, hopefully we can better test the population and quarantine suspected cases to contain it. However, it will be especially important to better treat the most serious cases. Why ? Because a more deadly flu epidemic is on the horizon. This year, hospitals will have to deal with this incredible double viral threat .
The first problem will be determining which virus infects each patient. “Influenza, Covid-19 and other seasonal respiratory illnesses are indeed virtually indistinguishable on the basis of symptoms alone “warns Barbara Rath of the University of Nottingham. “Even the loss of taste and smell, which many people contract with Covid-19, is not unique to this disease “.
Thus, we will need more and better diagnostic tests to first determine which bend load should be addressed . As Debora MacKenzie indeed points out in The Guardian, the consequences for hospital staff are not the same. “With Covid-19 , you need full protective equipment, while today there are vaccines to protect against the flu “.
It will also be a question of evaluating from the start the behavior of SARS-CoV-2 with other respiratory viruses in circulation.
Hostilities will begin as early as September with the first colds. The respiratory syncytial virus (RSV) will follow, in October and November, capable of weakening the youngest and the oldest among us. Then will come the flu, capable of raging until spring. As a reminder, it causes on average 12,000 deaths in France each year .
These different waves follow each other like this because of a phenomenon called "viral interference". Basically, if a virus is installed, another must generally wait its turn to take its turn. The question now is how Covid-19 is going to fit in the middle of this "viral chub".
Unfortunately, not all viruses behave the same way. It can indeed happen that we are infected by two viruses at the same time . This is why the coming flu epidemic is so worrying. Moreover, it is important to remember that the first person to die from Covid outside of China (a 44-year-old Filipino) also had the flu.
It is not known whether or not this second viral load exacerbated the risk of death for the victim . All we know is that this one was quite young. “Thus we assume that the outcome of this co-infection is not excellent “, warns Florian Krammer of Mount Sinai School of Medicine in New York.
Similarly, we also know that in Wuhan, in January and February of this year, Covid-19 took hold while the flu was still circulating in the region. And we know that many patients had both viruses .
According to the doctors, this co-infection did not increase the mortality rate of those concerned, compared to people with only Covid. On the other hand, they had more heart lesions and suffered from more inflammation. This was probably the result of an overreaction of the immune system facing two threats at the same time.
Finally, what will happen this winter? Only the future will tell us. Optimists will be banking on significant viral interference, hoping that outbreaks emerging as early as this fall will keep Covid-19 at bay . For their part, the less optimistic will fear a parallel viral evolution . Unfortunately, the latter scenario could be much more difficult to manage.
