The SARS-Cov2 pandemic remains associated with many concerns. One of the them is the realfrequency of likely re-infection and subsequently the level of protection conferred bythe acquired immunity following primary-infection. We propose to analyze a large set oflaboratory data produced since the early beginning of the SARS-Cov2 spread in the Frenchpopulation to identify recurrent infection events and, more generally, gain insight aboutinfection kinetics.