Before revision: Based on a simple analysis of the reports of Sant\'e Public France , we show that the real incidence during the second wave of the Covid-19 outbreak is around 60\% of the mean positivity of virological tests realized week after week in France.
After revision: Based on a simple analysis of the reports of Sant\'e Public France reports, that the Covid-19 outbreak is around 60\% of the mean positivity of virological tests realized week after week in France.