Bruno Mégarbane is head of the Medical and Toxicological Resuscitation department at the Lariboisière Hospital and professor of Intensive Resuscitation Medicine at the University of Paris.
To discover
Michel Houellebecq: "A civilization which legalizes euthanasia loses all rights to respect"
FIGAROVOX. - The Parliament validated the health pass, to encourage the French to be vaccinated. Do you think this measure is necessary to contain the epidemic? (What vaccination rate to stop the epidemic?)
Bruno MÉGARBANE. -
The health pass has two objectives. The first objective was to relaunch mass vaccination, as quickly as possible, after observing a gradual leveling off of first-time vaccines. This objective now seems attainable with the prospect of 50 million vaccinated at the end of August. Since mid-June, a speed race has started with viral contaminations which are progressing at an exponential rate (doubling time of the order of 5-7 days; high reproduction rate of 2, i.e. one infected person in contaminates two others). For vaccination to succeed in decoupling the progression of contaminations from that of cases admitted to hospital, it is necessary thatit is effective (with the 2 doses) in the greatest number of people over the age of 50 and / or at risk of developing a severe form of COVID-19. However, vaccinating all vulnerable people, some of whom are isolated, desocialized or even antivax, within a period as short as the summer, is complicated. A high vaccination rate of the general population (including adolescents from 12 years of age) would therefore reduce the level of viral circulation in the population and, in turn, reduce the risk of contamination of these fragile people. It should be known that the main vector of viral circulation and therefore of contamination is the young population, which lives from social interactions and mixing at work, in places of culture and leisure. For'to offer young people a life as close as possible to normal, without further fear of the handicaps of a long-term COVID or the exceptional severe form of respiratory COVID, vaccination is today the only reliable long-term remedy. So much so that everyone gets vaccinated as quickly as possible.
The second objective of the health pass is to secure places of social life, culture and leisure, in order to allow them to be opened without danger for those who frequent them. The health pass is a guarantee against confinement and a pledge for places of socialization such as restaurants, bars and nightclubs, previously identified as places of genesis of clusters of contamination, not to relive the same moments of socio-economic difficulties as in previous waves. The constraint that the health pass could exert against individual freedom (that of moving everywhere without giving a reliable guarantee of non-contagiousness) at the risk of contaminating the other therefore becomes the path for safe freedom, while respecting safety. others.
Collective immunity to significantly reduce virus circulation has been determined at 85% of the total population.
This figure will be difficult to reach quickly, even with the introduction of compulsory vaccination.
This remains a theoretical value that will have to be validated in an observational population study.
It is not excluded that at lower immunity values, it is not only possible to decouple the contaminations curve from that of the pressure exerted on hospitals but also to allow a spontaneous decrease in contaminations, as observed for a few days in the past. UK.
In my opinion, the conditions today are perhaps not yet all met, to remove the barrier gestures.
Bruno Megarbane
Should we maintain barrier gestures and wearing a mask, despite the health pass, to prevent any contamination?
As long as the level of vaccination of people who are fragile or at risk of serious or even fatal COVID and that of the general population remain insufficient, as still observed today in France, barrier gestures and wearing a mask must remain the norm in places where contamination occurs.
In the presence of a weak viral circulation with a regressive dynamics of the epidemic (as in June 2021), they can be limited to closed public environments.
During a phase of epidemic progression or high circulation of the virus, their fields of application can be extended, ideally in a way adapted to the epidemic situation of each territory.
The question of removing the barrier measures within a place governed by the sanitary pass is quite another. As early as April, the health authorities authorized the lifting of barrier gestures when vaccinated people who know each other meet together (typically during family or friendly meetings), except in the presence of an extremely vulnerable person. . Well applied and controlled, the sanitary pass could make it possible to reproduce such circumstances in the places it governs, even in the presence of people who do not know each other. In my opinion, the conditions today are perhaps not yet all met, to remove the barrier gestures: let's start applying the sanitary pass without creating any misunderstanding while the instructions for wearing the mask in theopen space of some city centers are increasing; expect an increase in the vaccination rate of the general population and that the health pass turns into a virtual vaccine pass (from mid-September with the delisting of comfort screening tests); let's wait to be sure that the 4th hospital wave is behind us.
With the observed rate of progression of contaminations (higher than in other waves), there is no doubt: a health disaster would have struck in the absence of the vaccine.
Bruno Megarbane
While the French are encouraged to be vaccinated and the health pass introduces strict measures, is there a risk of a fourth wave occurring?
Contaminations have been increasing since the end of June at an exponential rate, due to the prevalence of the delta virus, which is very contagious, now representing more than 90% of new contaminations. The 4th wave is here. Hospital and intensive care admissions for severe forms of COVID-19 have clearly resumed for a few days, although we do not know how quickly this progression will take place and to what peak. Thus, since this weekend, the number of people entering intensive care for COVID-19 is greater than the number of leaving and the number of patients hospitalized in intensive care has stopped decreasing.
It is usual to say that hospital admissions follow contamination with a delay of 3 weeks. This deadline is respected once again. But then, can we hope for a 4th hospital wave of lesser importance than those of the 3 previous epidemic peaks? This is the key question that no epidemiologist can yet answer definitively. All models consider optimistic scenarios as well as catastrophic scenarios. By analogy with the epidemic evolution in the United Kingdom, which seems to take place a month and a half in advance, we can hypothesize that the peak of contaminations could occur in France during the 2nd week of August with 50 to 60,000 contaminations / day.
With the observed rate of progression of contaminations (higher than in other waves), there is no doubt: a health disaster would have struck in the absence of the vaccine. Hopefully vaccination will warn us of such a risk. It certainly will be. We cannot however rule out a wave at the hospital which will reach its peak at the start of the school year in September. The 4th wave will be the wave of the unvaccinated. The health pass, applied routinely at the start of the school year, will then be felt by the vast majority of French people as a bulwark of protection against disease. Hopefully it is enough to avoid reliving a new confinement. The British example will be very interesting to analyze in the days to come.
