This May 13th, a study from the Institut Pasteur has been released in Science magazine and says that by May 11th, as France started to exit containment, 4.4% of the French population, or 2.8 million people, have been infected by coronavirus. The Institut Pasteur gives a margin between 2.8 and 7.2, that is to say, between 1.8 and 4.7 million people.
Searchers at the Institut Pasteur remind that “if about 65% of the population was immune, it would be possible to say the epidemic is under control because of immunity only. Our results show then that without a vaccine, herd immunity will not be enough to avoid a second wave at the end of lockdown. Effective controlling measures should be upheld beyond May 11th”.
But the study is also giving positive details and shows lockdown enabled to significatively lower the propagation of the virus and the reproduction rate, that is to say the number of people contaminated by one carrier: this rate moved from 2.90 to 0.67 during these 55 days of confinement – for the record, it is considered that when this reproduction rate moves below 1, the epidemic draws back.
The study also focuses on the lethality of coronavirus and notices that 3.6% of people infected have had to be hospitalized, as 0.7% of them died of coronavirus. Age is a major factor: the study shows mortality reaches 10.1% in people over 80 years old and 0.001% in people under 20 years old.