Recent research published in The European Physical Journal B offers an interesting explanation for the sharp decline in deaths from Covid-19 in the United States between August 2022 and March 2023. Although vaccines have played a crucial role in fighting the pandemic, it appears that a change in the molecular structure of the spike protein of SARS-CoV-2 was a decisive factor in reducing the severity of infections. • The context of the pandemic During the winters of 2020 and 2021, the United

Tag-uri: Coronavirus