A tentative tracking of the SARS-Cov2 pandemic in France, based on a corrected SIR model including vaccination effects

We developed successive extensions of the SIR model in order to track dynamics SARS-Cov2 disease. The analysis health system available data is published a chronicle accessible on net: https://corona-circule.github.io/lettres/ . This was initiated late march 2020 and up now contains 50 issues. A constant concern reliability data: for instance, we very soon evidenced that number confirmed cases, because asymptomatic carriers erratic testing policy, hugely underestimated. By end made basic change which consisted accounting contagiousness time (SIR-tcc) instead probabilistic evolution infection assumed so far. Recently completed this SIR-tcc vaccination effects properly group immunity threshold. Calculations were performed using Excel facility (Microsoft), allowing manual fitting parameters. results have dealt with large countries, but focus here regarding France. Further pieces information are also presented, help elucidating some factors responsible complex history pandemic dynamics. ( submitted dec 14 th 2021 )