EPIDEMIC With the seventh wave of coronavirus behind us, the start of the school year and the arrival of autumn could form a cocktail for a strong epidemic recovery
It's back to school, and Covid-19 did not stay on vacation.
Will we be faced with an eighth wave in the coming weeks?
In addition to monitoring indoor air quality, the emergence of new variants or sub-variants will be essential.
What about immunity? New vaccines should complete the arsenal available to us in the coming months, especially since the models are now struggling to give caregivers an outline of the future milestones to be crossed.
Vacations are over. The seventh wave of Covid-19 is over. Back to school soon. And soon the eighth wave? “The most likely scenario is that of an epidemic peak at the start of the school year, estimated a few days ago Brigitte Autran, immunologist and president of the Committee for monitoring and anticipating health risks, the entity which succeeds the Scientific Council. Will it be due to a new variant or the return of the cold? We are not diviners, but it is almost certain that there will be a wave in the fall”.
So, what sauce could the coronavirus eat us this fall? Which variants are likely to generate new waves? And what vaccines and tools do we have to prevent them? 20 Minutes makes its point of return to the virus.
Mini school sanitation protocol, indoor air quality issue
The government has planned a protocol for this new school year at the "base" level, the lowest of the new health framework. It provides for students to be welcomed face-to-face, in primary school as well as in middle school and high school, without wearing a mask. Physical and sporting activities will be allowed indoors and outdoors without restriction. And no limitation of mixing between groups of students is on the agenda.
Respect for barrier gestures, such as washing hands and airing the premises, is still recommended. Enough recommendations? “Back to school is a special time that must be monitored, warns Professor Bruno Lina, virologist, and director of the National Influenza Reference Center for the south of France. In terms of the calendar, based on the experience of the two previous autumns, this period, which corresponds to the resumption of school and work, a mixing of the population, a cooling of temperatures, and a drop in outdoor activities, forms the cocktail for a strong epidemic recovery”.
Raised in the summer of 2020, the issue of indoor air quality remains, for many scientists and doctors, too little addressed. “The importance of renewing the air infuses more and more, and the use of CO2 sensors can help raise awareness. But we must act, and faster, insists Professor Lina. This is a major issue in the school environment, but also professionally and personally. At the beginning of the 20th century, work was done on water quality to reduce the transmission of a number of infectious diseases. From now on, we have to work on the quality of the air”.
Russian roulette variants
If a new wave were to break, what variation would it bring? In its opinion of July 19, the Scientific Council is counting on three scenarios. “The first hypothesis is that we have a new wave of the BA.5 sub-variant of Omicron or a descendant that has not yet appeared advances, Professor Lina. When analyzing the competition between the variants, BA.5 has the greatest potential for dissemination, due to its high transmissibility and its level of escape from post-vaccination and post-infectious immunity”.
But “we are also closely monitoring other sub-lineages, in particular BA.2.75, which appeared in India, he adds. For now, laboratory studies and the reality of its propagation have shown that it is less efficient than BA.5”. In the Omicron family, scientists are also looking closely at “the BA.2.12.1 sub-lineage, which has circulated widely in the United States to the point of competing with BA.5. But the latter was also more efficient there, continues the virologist. Today, BA.5 and its derivatives predominate on a planetary scale, followed by BA.4 and its derivatives, little seen in France but present in Africa and South America”.
Last scenario, the most dreaded: "a new variant highly contagious and with a significant immune escape", indicates Professor Lina. However, "other sub-variants have emerged in the world in recent months and there is no reason to say that there will not be a new variant emerging outside the Omicron group", warns Mircea Sofonea, lecturer in epidemiology and evolution of infectious diseases at the University of Montpellier. To date, “none have been detected significantly on a planetary scale, observes Professor Lina. We have to follow this closely”.
New vaccines and new boosters?
To counter the virus and all its strains, new vaccines should in the coming months complete the arsenal we have. “Among these new vaccines, with messenger RNA and recombinant protein, there are interesting elements in terms of the quality of the immune response, rejoices Professor Lina. Enough to broaden and improve the spectrum of antibodies developed for future booster shots, and offer more effective protection against Omicron”.
On Monday, the Pfizer-BioNTech duo announced that it had urgently filed an application with the American drug agency, the FDA, to authorize its effective new generation vaccine against BA.4 and BA.5 from Omicron. Objective: to ensure the first deliveries in September in the United States. But on this side of the Atlantic, “the timetable is vaguer and could be delayed, underlines Professor Lina. Companies must file applications for their vaccine to be evaluated by regulatory agencies, agencies which will then have to give the green light on their use.
Pfizer-BioNTech plans to file its application for authorization with the European authorities at the end of the year. “If we add the logistical details, will we have these vaccines when we need them to prevent the next wave? Not sure, says the virologist. Initially, it will certainly be necessary to rely on current vaccines, which target the original strain of the virus, even if they are a little less effective and shorter, they are essential in the short term.
Declining immunity
At the same time, “the immune decline continues, warns Mircea Sofonea. The protection conferred by the last booster or the last infection decreases and may soon reach a level low enough to promote an epidemic resumption. When? We cannot predict it, and we will no longer have to rely on the models of the Institut Pasteur. “The models have become too complex to establish: between the number of doses received, the age groups, the level of immunity, and the multiplication of variants, there are too many parameters to establish the trajectories, explains the epidemiologist. In addition, the State has withdrawn from research and allocated funding, which means that today, the future looks hazy: we no longer have the necessary means to establish our models”. Modeling, however “requested by the CHUs to anticipate the impact of waves on the organization of care, and crucial to optimize the deployment of vaccine campaigns”.
And recall campaigns should soon intensify. Even if the health pass is no longer required, “it is up to everyone to judge their immunity, insists Professor Lina. People over 80 whose last booster or infection was more than three to four months ago have already lost their protective immunity significantly and need a quick booster. This also applies to those over 60 with comorbidities. For the youngest, this period is 5 to 6 months”.
Because today, “we know, the Covid-19 will live with us for years, so we have to learn to live with it, recalls Professor Lina. And for that, it is up to everyone to act to avoid chains of transmission”.
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