Photo: Ted Shaffrey Associated Press
The duration and degree of confinement may be reduced when effective treatments or a vaccine have been discovered, according to the team of american researchers.
Several periods of social distancing will likely be required until 2022 in order to prevent that the new coronavirus does not engorge the hospitals of the sick in the United States, say Harvard researchers in a study published Tuesday by the journal Science.
The team from Harvard has modeled the pandemic COVID-19, the disease caused by the virus, the assumption being that it would be seasonal like other viruses of the same family, the coronavirus responsible for the common cold, that love the winter.
Their simulation had to accommodate the many unknowns on the newcomer, named SARS-CoV-2), in particular on the level and duration of immunity acquired by a person who is infected.
“A one-time measure of social distancing will likely be insufficient for the impact of SARS-CoV-2 remains within the limits of the capacity of intensive care units in the United States “, summarized one of the authors, Stephen Kissler, in a conference call Tuesday with reporters.
“In the absence of treatment, with intermittent periods of social distancing will likely be required “, he said.
The duration and degree of confinement may be reduced when effective treatments or a vaccine have been discovered. By then, it will oscillate between containment and openness in order to prevent a new wave and allow the health systems to inflate their intensive care units.
Marc Lipsitch, professor of epidemiology, explains that, in accepting periods of infections is higher during the déconfinements episodic, the virus will inevitably contaminate a growing proportion of the population (ideally, the younger and less vulnerable, who are less likely to die).
This will make more people sick, but will present the advantage to gradually build up the herd immunity of the population, that is to say, the level at which there will be more than enough people who may be contaminated the virus continues to circulate.
Too much containment, conversely, prevent the build up this herd immunity, have simulated the researchers, who conclude that the most effective approach is to maintain intermittent measures of social distancing (containment, closure of schools and businesses…).
It is not yet clear if the people becoming infected will develop immunity to short or long. For virus cousins, like those of the common cold, immunity is eroding after a year. For SARS, it is long.
One thing is almost for sure, according to the authors of the study : the new coronavirus is not going to disappear overnight. It is unlikely, according to them, that the immunity is strong enough and durable enough for the coronavirus disappears at the end of the first wave that we are experiencing at the moment (unlike the SARS of 2002-2003).
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