Covid-19 infection will shift to younger children as the adult community becomes immune either through Covid vaccination or exposure to the virus.
The study, published in the journal Science Advances said such shifts have been observed in other coronaviruses and influenza viruses.
Citing an example of Russian flu, the researchers said, "During the 1889-1890 pandemic, sometimes known as the Asiatic or Russian flu -- which killed one million people, primarily adults over age 70 -- may have been caused by the emergence of HCoV-OC43 virus, which is now an endemic, mild, repeat-infecting cold virus affecting mostly children ages 7-12 months old".