People who don’t get vaccinated against COVID-19 should expect to be reinfected with the coronavirus every 16 to 17 months on average, according to a recent study
Since COVID-19 hasn’t existed for long enough to perform a long-term study, researchers at Yale University and the University of North Carolina at Charlotte looked at reinfection data for six other human-infecting coronaviruses, including SARS and MERS.
The research team looked at post-infection data for six coronaviruses between 1984-2020 and found reinfection ranged from 128 days to 28 years. They calculated that reinfection with COVID-19 would likely occur between 3 months to 5 years after peak antibody response, with an average of 16 months. This is less than half the duration seen for other coronaviruses that circulate among humans.
“We tend to think about immunity as being immune or not immune. Our study cautions that we instead should be more focused on the risk of reinfection through time,” Alex Dornburg, senior study author and assistant professor of bioinformatics and genomics at UNC, said in the statement. Study estimates are based on average times of declining immunity across different coronaviruses, the researchers. At the individual level, people have different levels of immunity, which can provide shorter or longer duration of protection based on immune status, immunity within a community, age, underlying health conditions, environmental exposure, and other factors.