COVID-19 may become childhood disease in few years: Study
COVID-19 may behave like other common-cold coronaviruses in the next few years, affecting mostly young children who haven't yet been vaccinated or exposed to the virus, according to a modeling study published on Thursday. The US-Norwegian team noted that because COVID-19 severity is generally lower among children, the overall burden from it is expected to decline as SARS-CoV-2 becomes endemic in the global population.
Risk of infection will likely shift to younger children: Study
"Following infection by SARS-CoV-2, there has been a clear signature of increasingly severe outcomes and fatality with age," said Ottar Bjornstad from the University of Oslo in Norway. "Yet, our modeling 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.
Such shifts have been observed in other coronaviruses, influenza viruses
The study, published in the journal Science Advances, noted that such kinds of shifts have been observed in other coronaviruses as well as influenza viruses as they have emerged and then become endemic. "Historical records of respiratory diseases indicate that the age-incidence patterns during virgin epidemics can be very different from endemic circulation," Bjornstad said.
Previous exposure to COVID-19 would lessen severity of the disease
Bjornstad, however, cautioned that if an immunity to reinfection by SARS-CoV-2 wanes among adults, the disease burden could remain high in that group, although previous exposure to the virus would lessen the severity of the disease.
Vaccination provides stronger protection than exposure to COVID-19: Bjornstad
"However, research on COVID-19 shows that vaccination provides stronger protection than exposure to the SARS-CoV-2 virus, so we encourage everyone to get vaccinated as soon as possible," he explained. The team developed a "realistic age-structured (RAS) mathematical model" that integrates demography, degree of social mixing, duration of infection-blocking, and disease-reducing immunity to examine potential future scenarios for age-incidence and burden of mortality for COVID-19.
RAS model also incorporates a variety of scenarios for immunity
The RAS model also incorporates a variety of scenarios for immunity, including both the independence and dependence of disease severity on prior exposure, as well as short-term and long-term immunity.
Prediction holds true only if reinfections produce mild disease: Professor
Jessica Metcalf, an associate professor at Princeton University in the United States noted that this prediction is likely to hold only if the reinfections produce only mild disease. "However, the burden of mortality over time may remain unchanged if primary infections do not prevent reinfections or mitigate severe disease among the elderly," she further added.
