A study looking at the resurgence of COVID-19 cases last summer and into the fall across the U.S. and Europe suggests adults between 20 and 49 years old are the largest spreaders of the virus.
“As of October 2020, individuals aged 20-49 are the only age groups sustaining resurgent SARS-CoV-2 transmission with reproduction numbers well above one, and that at least 65 of 100 COVID-19 infections originate from individuals aged 20-49 in the US,” the researchers state in their study published this month.
Researchers used cell phone location data that includes more than 10 million people plus publicly available information on the spread of the virus.
They say, specifically, adults between 35-to-49 contributed to 41% of the onward spread of COVID-19 last summer. That compares to 2% from kids younger than ten, and the 2.5% contribution to spread of the virus from those between 65 and 79.
After schools reopened, in October 2020, researchers say the 20-to-49-year-old bracket still contributed more to the spread of the coronavirus.
"Unlike pandemic flu, these adults accounted after school reopening in October, 2020 for an estimated 72.2% of SARS-CoV-2 (COVID-19) infections in the US locations considered, whereas less than 5% originated from children aged 0-9 and less than 10% from teens aged 10-19,” the report states.
The team concluded that “changes in mobility and behavior among the broader group of adults aged 20-49 underlie resurgent COVID-19 in the US in 2020.” They also suggest “additional interventions” including “mass vaccination” among the 20-to-49 age group “could bring resurgent COVID-19 epidemics under control and avert deaths.”
The CDC and their vaccine advisory panel have recommended health care workers, long-term care staff and residents, and frontline essential workers be prioritized for vaccines.
"You don't want to deprive them to get the younger ones, because they're the ones that are going to wind up in the hospital and have a higher rate of death," Dr. Anthony Fauci told CNN. "What we don't want to do is to neglect them."
Health experts argue older patients are having more severe symptoms from COVID-19 and a higher death rate, and should be prioritized for the vaccine when supply is still not meeting demand.