The response to the COVID-19 pandemic prompted abrupt and potentially lasting changes to human behavior, including the types of direct contact that enable transmission of common pathogens. Although the handshake and other types of physical contact are gradually returning, they have been on an extended hiatus. Such changes have already altered the epidemiology of a broad range of infectious diseases, including influenza, measles, and norovirus, and will likely continue to affect their age distribution, severity, and typical seasonal patterns. Changes to contact patterns may also nudge the evolutionary trajectory of pathogens, as they adapt to new norms of less human contact. Initiatives to measure social contact patterns through time and track their effects on the epidemiology of endemic pathogens are essential to both manage the potential for resurgence of common infections and to reenergize control efforts. There are two fundamental determinants of the dynamics of directly transmitted infectious diseases: the human contact that enables transmission and a pathogen’s biological natural history. Reductions in human contact that occurred during the COVID-19 pandemic have substantially affected patterns of circulation of other pathogens (see the figure). Reported incidence of most directly transmitted infections fell to virtually zero in early 2020 amid initial lockdown measures. Although these declines may have partially been due to gaps in reporting, they mostly reflect true reductions in disease incidence. As restrictions were relaxed, circulation of certain infections resumed—in some cases, with shifted seasonal patterns—but they have yet to return to their pre-pandemic levels…
From Science: https://www.science.org/doi/10.1126/science.abp9316