What have we learned about COVID-19 in 2020? Ten hypotheses explaining the differences in incidence and mortality from COVID-19 between countries

Coronavirus disease 2019 pandemic is one of the most difficult challenges for modern medicine and health care. Since the beginning of its outbreak in different regions of the world, researchers have noticed differences in incidence and mortality rates. We herein present ten hypotheses that were a topic of scientific discussions and might explain this observation. Cultural, demographic, sociological characteristics of societies, differences in healthcare systems and vaccination schedules, genetic polymorphism, and other factors can serve as variables affecting the pandemic’s course in the world’s different regions. Further study of those hypotheses might provide us with valuable insight and broaden knowledge in this unprecedented epidemiological situation.

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