Abstract
To verify if lethality and diffusivity of Covid-19 correlated with percentage of people vaccinated in different countries and whether results on these indicators were comparable under different types of vaccines. A linear regression analysis was conducted between vaccines/inhabitant, new cases/inhabitants and ratio deaths/cases. A comparison between the three indicators was carried out in countries subdivided by kind of vaccine. The proportion of vaccinations/inhabitants correlates negatively with proportion of deaths × 100 cases (R = -3.90, p < 0.0001), but didn't on incidence of new cases. Countries with prevalence of mRNA vaccines were similar to others on incidence of new cases; but a lower lethality of Sars-Cov2 was found than in countries with prevalence of viral vehicle vaccines (F = 6.064, p = 0.0174) but didn't against countries with prevalence of inactivated vaccines. The higher is the proportion of vaccine/inhabitant in a given country, the less is the fraction of infected people who die.