The current COVID-19 wave will likely be mitigated in the second-line European countries

Samuel Soubeyrand; Melina Ribaud; Virgile Baudrot; Denis Allard; Denys Pommeret; Lionel Roques

For countries where the outbreak started later than for the first impacted countries, a complementary approach to forecast the mortality dynamics can be adopted: it consists in comparing the dynamics of interest to those of countries that are ahead in time. Typically, media commonly use visualization and data science tools that jointly show curves of mortality for several countries and allow the analyst to guess which trajectory is followed by the country of interest. Thus, heuristically, the countries ahead in time with respect to COVID-19 mortality are used as predictors. One of the advantages of this intuitive approach is that the real dynamics used as predictors intrinsically include the processes and structures underlying the host population, the pathogen evolution, the health system, the control measures, the decision making and even the data collection. One of the drawbacks, for example in the case of COVID-19 at present, is that there may be a low number of countries ahead in time compared to the country of interest and therefore no adequate predictor among the reduced list of predictors.