The paper presents the results of scientific research on the impact of preventive measures, namely immunization of the population, on the spread of the Covid-19 virus. The study's primary purpose is to conduct a cluster analysis of European countries to analyze the incidence of the population, the number of deaths, and cases of complete recovery, depending on the number of vaccinated population. Systematization of literature sources and approaches to solving the problem of establishing public confidence in vaccination and theoretical proof of the effectiveness of vaccinations against diseases for which this may have shown that this issue was relevant before, and a new peak of interest in 2021. The urgency of solving this scientific problem is that the Covid-19 pandemic for the second year does not slow down and take many people's lives around the world. Among the effective ways to stop it is to maintain social distance, use personal protective equipment, but not enough, so mass vaccination of the population is a necessary preventive measure. The study of the issue of grouping countries depending on the rate of resistance to the virus and the number of vaccinated population in the article was carried out in the following logical sequence: 1) collection and processing of statistics; 2) conversion of absolute indicators into relative, depending on the population in the country; 3) data normalization; 4) application of cluster analysis. The methodological tools of the study were methods of statistical data processing, the process of k-means cluster analysis, Harrington's strategy for data normalization. The object of the study was to select spatial indicators of the vulnerability of European countries to Covid-19. The study empirically confirms and theoretically proves that the Covid-19 pandemic is developing differently and differentiated vaccination policies in the studied countries. As a result of the cluster analysis, a group of countries (Austria, Belgium, Germany, Greenland, Greece, Denmark, Ireland, Iceland, Spain, Italy, Liechtenstein, Luxembourg, Malta, Monaco, Netherlands, Portugal, France, Switzerland, Sweden) identified should become a model for others. It is characterized by a high vaccinated population and relatively low growth rates of the infected population at a relatively low mortality rate.