People in Singapore are having fewer children nowadays (file photo). Photograph:( AFP )
COVID-19 Study: The research published in the journal Science Advances, noted that such shifts have been observed in other coronaviruses and influenza viruses as they have emerged and then become endemic.
In the next few years, COVID-19 may act similarly to other common-cold diseases, affecting mostly young children who have not yet been immunised or exposed to the virus, according to new research.
The following infection by SARS-CoV-2, there has been a clear sign of increasingly severe outcomes and fatality with age, Ottar Bjornstad, of the Department of Biology at the Pennsylvania State University, said.
"Yet, our modelling results suggest that the risk of infection will likely shift to younger children as the adult community becomes immune either through vaccination or exposure to the virus," he said.
As additional coronaviruses and influenza viruses have arisen and later become endemic, comparable changes have been documented, according to Bjornstad.
The age-incidence patterns during virgin outbreaks might be significantly different from endemic circulation, according to historical records of respiratory illnesses.
"For example, ongoing genomic work suggests that 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," Bjornstad noted.
Such alterations have been found in other coronaviruses and influenza viruses when they arise and subsequently become endemic, according to the study, which was published in the journal Science Advances.
The researchers created a "realistic age-structured (RAS) mathematical model" for the study, which was published in the journal Science Advances.
They looked at disease burden in the short, medium, and long term—1, 10, and 20 years, respectively—as well as for 11 different countries with vastly different demographics, including China, Japan, South Korea, Spain, the United Kingdom, France, Germany, Italy, the United States, Brazil, and South Africa.
The model predicts different outcomes for different nations due to differences in demography.
"Given the marked increase of the infection-fatality ratio with age, countries with older population structures would be expected to have a larger fraction of deaths than those with relatively younger population structures," said Nils Chr. Stenseth, Professor of ecology and evolution, University of Oslo.
"Consistent with this, for example, South Africa—likely due, in part, to its younger population structure—has a lower number of deaths compared to older populations such as Italy. We found that such 'death disparities' are heavily influenced by demographics. However, regardless of demographics, we predict a consistent shift of the risk to the young," he added.
(With inputs from agencies)