An 8th wave of Covid started in September 2022 in France. The Covars has issued its hypotheses with several possible scenarios in the fall of 2022. Date of the peak, evolution of the variants, graph curves... Here is the summary of the forecasts.
[Updated October 25, 2022 at 11:36 a.m.] For the past few weeks, the number of Covid infections has been increasing, especially among school children. The epidemic is currently characterized by an almost total circulation of NOT. 5 in our country. An epidemic recovery is indeed raging on the metropolitan territory since one month . The current epidemic wave is of moderate intensity and due to the same variant as that of the 7th wave . It remains potentially lethal in frail people at high risk of a serious form and in particular in immunocompromised patients who do not respond well to vaccination. In this context, them Covars , which replaces the Scientific Council, was contacted to give his assumptions about the 8th wave of the epidemic as well as his evolution over the next few months. Indeed, the Covid epidemic evolves in waves. To date, 8 waves are recorded between March 2020 and autumn 2022 , marked by the influx of patients to the hospital and intensive care . The 8th wave may' have a moderate impact if no new variants arrive “, estimates Anne-Claude Crémieux, infectious disease specialist interviewed at Sunday newspaper October 9. The first 7 waves 'were linked to the emergence of variants or sub-variants, hence the very numerous reinfections [...] The current wave, on the other hand, is - to date at least - not linked to the appearance from a new strain “, she details. Return in dates on the different waves of the Covid epidemic in 2020, 2021 and 2022.
Specialists speak more of a rebound of the 7th wave rather than a real 8th wave
An 8th epidemic wave started in France in September 2022. This rebound in incidence in mainland France is very likely linked to the resumption of social contacts and the sudden drop in temperatures (professional activities, reopening of schools) after the summer break, explains the Covars. Anne-Claude Crémieux, infectious disease specialist interviewed in the Journal du Dimanche indicates that a ' endemic-type scenario, with new waves of infections, more marked in autumn or winter as for the flu or other respiratory viruses, seems (...) the most likely '.' This 8th wave is made of the same variant as the one that circulated during the summer , she recalls this time at the microphone of France Inter October 10. Specialists speak more of a rebound of the 7th wave rather than a real 8th wave . You have to remember that we had the same phenomenon with the variant delta Last year. There had been a rebound also in the fall of 2021. Nevertheless, it is known that there are some new variants, which are a little worrying, in India or in different countries. But today, we remain quite calm because we do not see any epidemic emergence of these variants which would be particularly formidable. But to monitor, you have to keep testing yourself. This wave, carried by the subvariants of OmicronBA4 and BA5 a less direct hospital impact than earlier waves. Here is the forecasts reported by Covars.
► Short-term forecasts: According to the Mathematical Modeling of Infectious Diseases unit at the Institut Pasteur which produces short-term forecasts of COVID-19 hospital needs based on an overall model , the projections made with the data of October 17, 2022 anticipated that at the national level and in the regions, we were going to observe a plateau or a decrease in hospital admissions in the following days. Analysis of the growth rates of the various epidemiological indicators suggests that we could be very close to the epidemic peak. However, these encouraging signals need to be tempered as preliminary analysis of EMERGEN data suggests rapid growth you variant BQ.1.1 on the national territory. If this trend were to be confirmed, it could call into question the apparently initiated plateau/decline dynamics of the wave. This is a scenario that has been observed many times in the past, when a new variant emerges: the incidence of the 'historical' variant decreases while that of the emerging variant increases ; as long as the emerging variant represents only a small proportion of infections, the overall incidence of SARS-CoV-2 infections decreases but October 20, 2022 10 from the moment the emerging variant becomes dominant, there is a risk of an increase of the impact.
► Medium term forecast: COVARS is not aware of any modeling scenarios COVID-19 for fall-winter 2022-2023 for France, but scenarios have been produced for other countries, for the United States for example. In the scenario without the emergence of variants, the models do not anticipate a major rebound in hospitalizations. In the scenario with an emergence of variant the impact can be more important.
The 7th epidemic wave of Covid peaked in July 2022 and was carried by two sub-variants of Omicron BA.4 a BA.5 . ' Probably due to their ability to escape immunity acquired through infection and/or vaccination, especially if this has waned over time ', reports the European Center for Disease Control (ECDC) in a May 13 report. In mid-June, the average number of confirmed cases hovered around 40,000 per day.
Some epidemiologists have suggested a 6e vague , at the end of March 2022, with an incidence rate and a total number of positive cases which were going up. Nevertheless, this wave was smaller scale than previous waves (see curve below). According to figures from Public Health France, the number of cases gradually decreased around April 5 until reaching a plateau of around 20,000 new cases per day around May 20, 2022. the rise. Le pic de la 6e vague was around the 31 mars 2022.
The fifth wave of the COVID-19 epidemic started in early November 2021 . The incidence rate has increased sharply and exceeded the level reached in previous waves. Despite the increase in incidence observed in all age groups at the start of this 5th wave, the virus seems to have mainly circulated among the youngest . This wave first conveyed by the variant Delta , was then marked by the emergence of a new variant called Omicron . In this worrying context, the government has relied on a recall campaign . The incidence rate peaked around January 24, 2022 (with 3,800 positive cases per 100,000 population). The peak of hospitalizations was reached on February 7, 2022 with more than 33,000 people hospitalized. The curves then slowed down around mid-February. In March, we can say that France came out of the 5th wave.
On July 21, 2021, Prime Minister Jean Castex confirmed on TF1 that France had entered its fourth epidemic wave. At that date, the curve of hospitalizations was still low because we know that it takes on average 2 to 3 weeks for the increase in cases to affect the number of people hospitalized. The peak was reached in mid-August. The generalization of sanitary pass pushed the French to go to get vaccinated which made it possible to bring down the curve of hospitalizations. The peak of the 4e vague was reached at the mid-August 2021 (around August 12, 2021)
After experiencing a decline from November 16, 2020, the epidemic is started to rise again in mid-March 2021, with an average of new cases per day of 50,000 . ' Yes the third wave is here and it is hitting us hard' alerted the Prime Minister, Jean Castex, before the National Assembly on April 1, 2021. Monday March 29, 2021, the number of people in intensive care exceeded that of the peak of the second wave in the fall. This is the highest number since April 22, 2020. The health situation is particularly critical in Ile-de-France where hospitals are saturated. The highest number of critical care admissions was reached on April 12, 2021 with 495 new admissions. The peak of the 3rd wave was reached on April 12, 2021 for hospitalizations and April 13 2021 for resuscitations.
The Scientific Council alerted at the beginning of September 2020 to the occurrence at the end of that same month of a second epidemic wave . 'Circulation of the virus resumed during the summer of 2020 throughout France, particularly among young adults. The number of cases diagnosed each day reached 10,000 on September 1 “, he explained in a note of October 26. A drop in the numbers was observed in the second half of September (on average 15,000 new infections per day). As of October 1, 2020, ' there is an extremely rapid rise in the number of new cases , which follows a general drop in temperatures (drop reaching 25°C for the maximum in places) which began between September 20 and 25 depending on the region ', continued the Scientific Council. The epidemic then progressed in France to reach in mid-November [around November 15] a number of people hospitalized slightly higher than the peak of mid-April (about 32,000 people hospitalized every day between November 11 and 20. By mid-November, the epidemic was in decline . On December 14, 2020, the daily number of new cases hovers around 4,000. The peak of the 2e vague was reached between November 12 and 19, 2020 .
Since the first official cases recorded in France on January 24, 2020 by Public Health France , the numbers of new cases and new deaths from Covid-19 have increased dramatically increasing until the end of March . In other words, from the end of January to the end of March, France was in ascending phase . From April 3, 2020, the impact of the epidemic was major and ' France was in a high plateau phase 'indicated Jérôme Salomon, director general of health on April 10. The number of people hospitalized was the highest on April 14 (over 32,000) to drop gradually between April 20 and early June (around 15,000). Between June 15 and September 20, 2020, the number of hospitalized patients stabilized around 5,000 and the number of people in intensive care around 400: France was then in a low plateau phase . The numbers began to rise again in late August, leaving predict the start of a second wave. The first wave peak took place, according to the curves, between April 6 and April 10, 2020.
For each of the waves, the epidemic curve appears to follow the bell curve (see curves above). I formed it in a cloche (also called curve of Gauss in mathematics ) is typical of curves of evolution of an epidemic called 'by propagation' , as is the case with most human-to-human diseases (viral diseases). If we analyze the epidemic curve of a viral disease, we always notice an ascending phase at the beginning of the epidemic, then a bell shape which corresponds at the peak of the epidemic , a stagnation in the number of new cases and finally, a downward phase, where the number of cases gradually decreases. For some scientists, this typical 'bell' shape represents an indicator that would announce that the peak of the epidemic has been reached and that the disease is in a very decreasing phase.
Sources : Covid-19 epidemiological update, Public Health France // Geodès curves - Public Health France (hospital data) // Note from the Covid-19 Scientific Council: a second wave resulting in a critical health situation - October 26, 2020Source journaldesfemmes.fr