Covid-19. Will the BA.4 and BA.5 subvariants lead to a new epidemic wave in France? – West France

Is a rebound in the Covid-19 epidemic beginning in France? Since the end of May, the Covid-19 contamination curve has not been falling, it even shows the harbingers of a new increase in recent days. On average over the past week, 23,383 new positive cases of Covid-19 are now declared every day, according to figures from Public Health France of Monday June 6, 2022. This is a figure up 30% compared to an average of 17,825 new cases per day recorded on Monday May 30. Same trend for the comparison between the new cases announced each day by Public Health France and those of the previous week: +7% for May 30, +20% for June 2, +32% for June 6. With the Ascension Bridge and Pentecost Monday when fewer tests were carried out, the contamination figures are difficult to interpret for the past few days and the increase could be explained by a catch-up in screening examinations after these days. holidays. The arrival of the Omicron sub-variants, BA.4 and BA.5, could also partly explain this increase in cases. Also read: Covid-19. What we know about the BA.4 and BA.5 sub-variants, two new strains of Omicron A progression of BA.4 and BA.5 in France Currently, the BA.2 sub-variant of Omicron, which led to a resumption of the epidemic in March-April, remains the majority strain in France, with a proportion of 94% in the tests sequenced by Public Health France, according to the last point of the organization published Thursday, June 2. The BA.4 and BA.5 sub-variants from the same Omicron family currently occupy a minority position in France. However, detection is clearly on the increase: 0.8% for BA.4 and 5% for BA.5 in the latest Flash survey by Public Health France (week 20), compared to 0.5% and 1.5% for Flash week 19. “The circulation of the BA.4 and BA.5 sub-variants is increasing exponentially,” judges epidemiologist Antoine Flahault, director of the Institute of Global Health (University of Geneva). A wave of the two sub-variants already seen in Portugal These two variants which are progressing in France are indeed the cause of a rebound in the epidemic in Portugal during the month which has just passed. “Since mid-April, the rebound linked to the BA.4 and BA.5 sub-variants has taken place in Portugal and peaked towards the end of May. Today, contamination remains on a high plateau in the country, ”explains Antoine Flahault. During this rebound episode in Portugal, “there was pressure on the hospital, but they weren’t overwhelmed. As for the mortality rate, we have seen a rise since the end of April and the indicator has not yet reached its peak to date due to the lag with the increase in contamination. According to data from Our World in Data, a recognized platform for compiling international data for the Covid-19 pandemic, Portugal experienced a peak of nearly 3,000 cases per million inhabitants as of June 2, for this wave of contamination carried by the two sub-variants BA.4 and BA.5. A level ten times higher than that of around 300 positive cases per million inhabitants in France on the same day. But well below its peak for the first wave of Omicron BA.1 in January, which caused more than 6,000 cases per million population at the end of January in Portugal. What scenario for the coming weeks in France? According to epidemiologist Antoine Flahault, “we should see an increase in the circulation of the virus in France” in the days to come, linked to these two sub-variants. For him, “triply vaccinated French people should pass this wave well as they passed the BA.1 and BA.2 wave well. “And the consequences should be greater, as with previous epidemic episodes, for” the elderly, immunocompromised and not fully vaccinated. According to the scientist, there is no evidence that the two sub-variants have a greater virulence than their “cousins.” “I don’t think that the severity of BA.4 and BA.5 that we have seen in South Africa and Portugal is greater than that of BA.1 and BA.2. It is rather of the same order, ”clarifies the epidemiologist. So what could be the impact on hospitals? They should “experience an increase in hospitalizations following the increase in contamination, which could put them a little under tension, in particular with the difficulties known today in France. If we observe in France a progression of the BA.4 and BA.5 sub-variants, which seems to herald a new epidemic wave, like what happened in Portugal, a negligible difference is to be noted between the two countries. “Is the BA.5 wave in Portugal so big because they didn’t have a BA.2 wave, unlike most European countries? And, consequently, will France, which had a BA.2 wave, be better protected against the arrival of BA.4, BA.5? asks Arnaud Fontanet, epidemiologist at the Institut Pasteur and member of the scientific council, in Le Monde.

“The only favorable thing is the season” As we know, the high temperatures marked by more outdoor activities are unfavorable elements for the circulation of the virus, compared to the winter season. “The only favorable thing is the season”, emphasizes Antoine Flahault. Even if “we saw a rebound in Portugal in May, a hot month. So we are not immune. The epidemiologist goes further: “We can perhaps prepare for the return of a wave, with these variants or others, which could be stronger than the rebound of this summer. “And to conclude in the face of the current slight rebound: “Wearing a mask must be widely recommended to vulnerable people and encouraged for people in contact with them. »

Covid-19. Will the BA.4 and BA.5 subvariants lead to a new epidemic wave in France?