11:00 p.m., January 30, 2021
Professor of infectious diseases, member of the Academy of Medicine, Anne-Claude Crémieux, is a specialist in health crises. She is the author of “Governing the unpredictable: influenza pandemic, SARS, health crises” (Lavoisier editions, 2009).
Is the prospect of confinement receding?
Without knowing the results of the second flash survey aimed at measuring the penetration rate of the English variant in the country, we know that it is circulating so much that there is very little room for maneuver. The moment when the increase is going to be very rapid is approaching. Containment therefore remains probable. The question is: when will he intervene? The government is undoubtedly trying to buy time, and perhaps to act during the school holidays, which generate a decrease in the activity and therefore in the circulation of the virus. It is quite legitimate.
Isn’t it dangerous to wait?
For a few months, we began to tame the virus. The massive tests had cleared the fog over the number of contaminations; the braking measures were calibrated, the horizon cleared up with the arrival of vaccines. Even though it had been less effective, the lean fall containment had worked. We knew that the curfew could be useful. Then this new variant arose and it reintroduces uncertainty. Its reproduction rate reaches 1.5; or 50% more than the circulating strain. In Kent, where it first appeared and spread on a massive scale, actions that curbed the spread of the wild virus did not prevent its own. This leads us to have to recalibrate the braking measurements. But not necessarily to duplicate what the English did. The current thinking on the level of restrictions to put in place is understandable.
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Countries that confined early had shorter, less lethal first waves
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Has science shown that you have to strike “early and hard”?
Many studies have shown that countries which confined early had shorter and less lethal first waves. In my book, I listed the mistakes made during pandemics: minimizing, not preparing for “reasonably pessimistic scenarios”, not adapting plans to the real situation, etc. The impact of late decisions weighs in addition thereafter, for the better too. This is undoubtedly why Boris Johnson, faced with the tragic death toll of 100,000, understood the urgency to vaccinate quickly. And this is also why most of the countries which have almost eliminated the virus (Vietnam, Taiwan, Hong Kong, etc.) are those which were very affected by the SARS crisis in 2003. New Zealand is the exception. which proves the rule: without even having been struck at the time, it was able to avoid all these pitfalls. The Prime Minister has changed strategy, decided to eliminate the virus, at the cost of economic sacrifices, without allowing herself to be locked into the patterns drawn by her anti-influenza pandemic plan.
Shouldn’t the experience of English chaos prompt us to quickly put in place restrictions?
The English experience of recent weeks shows first that a containment lighter than the late lock-down put in place by London in the spring can slow the circulation of the variant. Economic life is not completely stopped; teleworking is encouraged but not everyone stays at home; children go to school, even if they are theoretically closed. Ten days after its entry into force, the first signs of deceleration were detected.
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This more transmissible virus is more difficult to tame but it is possible to contain it
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This is an important lesson, because the Institut Pasteur has shown in a study published in The Lancet that in France in March, it was also between D + 10 and D + 15 after the start of confinement that this trend took hold. was manifested. There was talk of a totally out of control situation in Great Britain, but the data suggests on the contrary that it is not inevitable. While this more transmissible virus is more difficult to tame, the attack rate, that is to say the percentage of contact persons infected by a single case, climbs from 11 to 15%, but it is possible to contain it! Even if the epidemic remains on a high plateau, with an R at 1. Another reassuring element: Public Health England, the equivalent of Public Health France, has just concluded that the age pyramid of infected people has not changed: children under 10 years of age are half the transmitters of the infection than adults.
Should schools be closed in France and across the Channel?
It is not because the English do it that it will have to be done here! We may be able to keep them open. It is one variable among others, which must be adjusted by taking into account the uncertainty induced by the variant. Data released there, such as a new study from the US Epidemic Control Center (CDC), confirms that schools are not a place of accelerating the epidemic. According to this study, most of the infected people, adults but also children, are outside of school. Second, the barrier measures were different on the two sides of the Channel, making it difficult to extrapolate from the English case. The CDC’s latest publication on schools also says that the main risk factor for a child of being infected is not going to school but not wearing a mask in class. This is good news: wearing a mask is protective; prevention works!
Is closing extra-European borders useful?
Faced with dangerous variants, the benefit-risk balance inevitably falls in favor of more restrictive measures. This is especially useful at the beginning when the variants still circulate little on the territory, but it is a measure of diffusion braking which remains important. A PCR test on departure, in any case, is not enough to guarantee that a traveler is not contaminated. The test must be repeated after a quarantine of seven days.
If containment was decided, should it be “tight” or light?
The study of movements, using data from telephone operators or from social networks, can inform us about the effectiveness of restriction measures and allow us to adjust them. Epidemiologist Vittoria Colizza has shown a dramatic drop in mobility during the first confinement (minus 65%), and less during the second (minus 30%). Imperial College London, which is probing the evolution of the epidemic in a sample of 150,000 people, has just explained that in England, mobility measured from Facebook data had fallen less during the third lockdown than during the first, hence “the absence of a net decline”. This parameter is a major element of analysis assistance.
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During curfew, people continue to travel too much
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Why is the current curfew ineffective?
Two factors can explain it: one is human, the other viral. If we stay on such a high plateau, it’s either because people continue to move around too much and therefore have too much interactions before or after 6 p.m., which is obvious in Paris. Either because the rapid penetration of the variant reduces the impact of the braking measures, and in particular of the curfew. What is the respective share of these two parameters? The answer is not evident.
Countries that have (almost) eradicated the virus are doing better. Is the zero Covid strategy a solution?
This strategy was possible in July and August. When the virus was circulating little, we could still hope to control the chains of contamination, deploy a test-trace-isolate strategy as aggressive as that of the countries which are doing well (China, Iceland, New Zealand). I don’t think we can do it today. To achieve this, it would first be necessary to impose a strict and long confinement and then to put in place a very effective policy of isolation and search for sources of contamination. But it would take an army of public health professionals on the ground, which we no longer have, and it would take months and resources to rebuild it. This does not prevent us from continuing to test-trace-isolate as many infected people as possible. Our salvation will come rather from a very rapid vaccination of the 14 million fragile people made possible by extraordinary medical progress. This will allow the health effects of the epidemic to be mitigated without resorting to repeated confinements, a strategy currently followed. The other emergency today is that the contact-tracing teams of the regional health agencies continue to focus on contaminations by variants. And also to make the conditions of isolation more effective: the Academy of Medicine, of which I am a part, pleaded very early for the opening of Covid hotels. It is still a good idea.
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