While there are fears of a resurgence of Covid-19 cases this fall, the epidemic no longer seems to scare anyone. Would the arrival of new vaccines and a sufficiently developed collective immunity be enough to stem the wave announced by the specialists? Professor Antoine Flahault, epidemiologist and director of the University of Geneva’s Institute of Global Health, responds to La Dépêche du Midi about a potential shortness of breath.
Among the scenarios, is the loss of momentum or even the end of the epidemic conceivable in the short, medium or long term?
In the short term yes, the summer epidemic wave is ending, although France still has a plateau of nearly 15,000 new cases and 35 deaths per day, which is double the level of last year at the end of the same era. Unfortunately, we are unable to predict the evolution of the pandemic in the medium and long term.
Was the epidemic situation the same as last year at the same time before the October 2021 wave?
The strong wave of October 2021 was due to the Delta variant which had caused a summer wave of moderate magnitude. If the Omicron BA.5 sub-variant came back in the fall and caused a new wave, then we would really be in a very similar situation to last year.
Could the expected wave in the fall be lower than expected? If so, thanks to what?
No one can accurately predict this pandemic more than a week in advance. Now, some of the scenarios imagined in the past have come true. We’ve seen three waves in eight months in 2022, so it’s tempting to predict another wave before the end of the year. But we don’t know! It is a possible scenario. For this to occur, a virus and a susceptible, i.e. non-immune, population are required.
Covid: what we know about Pfizer and Moderna’s new vaccines against Omicron validated by Europe
As for the virus, we still don’t see a new variant or sub-variant that could qualify for fall. It can come quickly from anywhere, like Alpha from Kent or Omicron from South Africa. We were able to see Omicron’s latest BA.5 sub-variant return thanks to the cold season. For this it should find a sufficiently large population that is still susceptible, after the summer wave this is not necessarily the case in Europe today. A prolonged pause waiting for a new variant cannot be ruled out. All the scenarios are on the table, from an extended hiatus to the return of a new wave that could very well be strong.
Will Omicron vaccines help eradicate or stem a possible wave of fall?
Available vaccines have never eradicated pandemic waves. They made it possible to lower the severity of Covid, without sufficiently preventing its transmission. One of the unknowns in which we find ourselves concerns the immunity acquired with the Omicron variant. Some studies suggest a “stealth variant”, which would go under the radar of immunity. That is to say, without leaving any immune memory of its passage through our body. In this case, adding a valence specifically directed against Omicron to the vaccine would be a waste of time and would not bring any benefit over the original vaccines. Other studies are more optimistic and suggest a promising future for these new vaccines. It is too early to decide. In a few weeks, with the experience of the Americans, we will know more.
How should the population behave in the face of this truce?
It is difficult to ask the population to maintain a high level of vigilance when the virus is circulating less. We see it, people relax their efforts, they want to live as before and it is understandable. Vulnerable people must continue their prevention efforts, for others it is difficult. Instead, it is up to the authorities to watch over these quiet times. They need to keep their health surveillance systems on alert. The authorities could also use this period to improve indoor air quality, the ventilation of closed places, which would prevent future waves whatever the new variants. Unfortunately, authorities tend to manage crises (effectively, moreover) rather than preparing for the future and investing in prevention and anticipation.