[azepoi]

Of course it's not really exponential. And even the simplest SIR toy model does not output an exponential solution, except as an aproximation at the start. My point was simply that it took several months between very low numbers at the end of the first lockdown and the decision to put a second albeit lighter lockdown in France and (at least parts of) Italy. So one should not be surprised that the virus was circulating for several months before the problem became really noticeable in february.