ABSTRACT The ongoing COVID-19 pandemic has led to more than 159 million confirmed cases with over 3.3 million deaths worldwide, but it remains mystery why most infected individuals (∼98%) were asymptomatic or only experienced mild illness. The same mystery applies to the deadly 1918 H1N1 influenza pandemic, which has puzzled the field for a century. Here we discuss dual potential properties of the 1918 H1N1 pandemic viruses that led to the high fatality rate in the small portion of severe cases, while about 98% infected persons in the United States were self-limited with mild symptoms, or even asymptomatic. These variations now have been postulated to be impacted by polymorphisms of the sialic acid receptors in the general population. Since coronaviruses (CoVs) also recognize sialic acid receptors and cause severe acute respiratory syndrome epidemics and pandemics, similar principles of influenza virus evolution and pandemicity may also apply to CoVs. A potential common principle of pathogen/host co-evolution of influenza and CoVs under selection of host sialic acids in parallel with different epidemic and pandemic influenza and coronaviruses is discussed.
【저자키워드】 polymorphism, sialic acid receptor, co-evolution, Influenza and coronavirus, 1918 H1N1 pandemic, 【초록키워드】 Evolution, coronavirus, pandemic, Influenza, COVID-19 pandemic, Variation, Epidemics, Influenza virus, virus, Epidemic, Asymptomatic, death, severe cases, Pandemics, CoV, receptor, General population, H1N1 influenza, mild symptoms, sialic acid, confirmed case, acute respiratory syndrome, infected individual, Fatality rate, CoVs, mild illness, Host, H1N1 pandemic, the United State, recognize, impacted, 【제목키워드】 coronavirus, Influenza, sialic acid,