Abstract

This research explores the multifractal dynamics of the daily number of vaccinated time series for COVID-19, considering six European countries (Belgium, Denmark, France, Ger-many, Greece, and Italy) using the Multifractal Detrended Fluctuations Analysis (MF-DFA). We calculate the multifractal spectrum í µí±“ (í µí»¼) and apply a fourth-degree polynomial regression fit to estimate the complexity parameters that describe the degree of multifractality of the underlying process. We find that the multifractal dynamics of all these countries are characterized by strongly anti-persistent behaviour or anti-persistent long-term correlations (í µí»¼ 0 < 0.5) a lower degree of multifractality, and small fluctuations are dominant in the mul-tifractal spectrum. Our findings shed light on the period of immunization of the population that adhered to the vaccination campaigns is short and that the application of new doses of vaccines must comply with this phenomenology to keep the people safe.