LAUSR

In recent times the debate about the possibility, and in some cases the hope, that the COVID-19 disease will become endemic has gained momentum. Indeed, in some cases, public opinion and scientists have proposed and enthusiastically welcomed this evolution, indicating a change of phase of the pandemic and a possible resolution of it. Infectious diseases can evolve in four scenarios, in relation to their biological characteristics (mutations that arise as a result of specific selective pressures might determine the occurrence of variants) and the Public Health measures implemented to contain the spread of the pathogen. Incidence, prevalence and geographical distribution of the disease, in fact, identify the conditions of extinction (the pathogen no longer exits, both in nature and in the laboratory, on a global scale), eradication (permanent zero incidence globally, so as not to require further interventions of Public Health: there is no risk of reappearance of the disease), elimination of the pathogen and the disease (zero incidence in specific geographic areas, following continuous Public Health interventions) and endemicity (constant presence and/or habitual prevalence of an infectious agent in a population within a geographic area with coexistence between human and the pathogen) (1, 2). The latter, therefore, requires a constant control of the epidemiological trend of the disease, in order to maintain acceptable levels of incidence, prevalence and mortality. While there are no examples of extinction, smallpox, and rinderpest represent examples of eradication, while polio and measles of elimination. That stated, is the evolution toward endemicity really desirable with a disease with high transmission and mortality rates such as the COVID-19? is the evolution toward endemicity really desirable? In this context, it is important to point out a few considerations about the health, social and economic burden of endemicity and the possible impacts of COVID-19 endemicity, summed up in the 4 E’s strategy, as follows.