Novel coronavirus may resemble common cold in future, scientists predict
SARS-CoV-2, the virus that causes COVID-19, may resemble the mild cold-causing coronaviruses that currently circulate in humans if it becomes endemic and most people are exposed to it in childhood, according to a study. The modeling study, published on Tuesday in the journal Science, is based on the research of the four common cold coronaviruses and SARS-CoV-1.
Model to predict trajectory of SARS-CoV-2 as it becomes endemic
The analysis of the immunological and epidemiological data for these viruses helped the researchers to develop a model to predict the trajectory of SARS-CoV-2 as it becomes endemic when the virus circulates in the general population. The researchers noted that four common cold-causing coronaviruses have been circulating in humans for a long time and almost everyone is infected at a young age.
Natural infection in childhood doesn't prevent periodic reinfection: Author
Jennie Lavine, from Emory University in the US, the first author of the study said, "Natural infection in childhood provides immunity that protects people later in life against severe disease, but it doesn't prevent periodic reinfection."
Endemic SARS-CoV-2 may become a disease of early childhood: Researchers
The research suggests that endemic SARS-CoV-2 may become a disease of early childhood, where the first infection occurs between three and five years old, and the disease itself would be mild. "How fast this shift comes depends on how fast the virus spreads and what kind of immune response the SARS-CoV-2 vaccines induce," they added.
Model suggests that SARS-CoV-2 may become endemic quickly
The model suggests that if the vaccines induce short-lived protection against getting reinfected but reduce the severity of the disease, SARS-CoV-2 may become endemic more quickly. "This model assumes immunity to SARS-CoV-2 works similar to other human coronaviruses. We don't really know what it would be like if someone got one of the other coronaviruses for the first time as an adult," Lavine said.
Severity of primary infections to determine childhood vaccinations
The researchers also noted that if primary infections in children are mild when the virus becomes endemic, widespread vaccination may not be necessary. "However, if primary infections become severe in children, childhood vaccinations should be continued," they added.
Fatality rates may wane in the near term: Epidemiologist
The model predicts that the infection fatality ratio for SARS-CoV-2 may fall below that of seasonal influenza (0.1 percent), once an endemic steady-state is reached. Ottar Bjornstad, a professor and epidemiologist at Penn State said, "A key take-home message from the study is that immunological indicators suggest that fatality rates and the critical need for broad-scale vaccination may wane in the near term."
Mass vaccination may be less critical once SARS-CoV-2 becomes endemic
The researchers said, "A safe and effective vaccine against COVID-19 could save thousands of lives in the first year or two of vaccine roll-out, but continued mass vaccination may be less critical once SARS-CoV-2 becomes endemic. Targeted vaccination in vulnerable sub-populations may still save lives."
