Adults aged 20 to 49 are the biggest disseminators of COVID-19 in the United States, according to British researchers who say that targeting vaccination at this age group can accelerate the reopening of schools.
A team at Imperial College London used cell phone data from more than 10 million people to estimate that 65 out of 100 infections still originated from people aged 20 to 49 in the United States.
They found that people in that age group were responsible for about 72% of cases after schools reopened in October. Less than 5% came from children and less than 10% from adolescents.
Adults aged 35 to 49 accounted for 41% of new cases by mid-August, compared with 35% for adults aged 20 to 34, according to the peer-reviewed study published in Science.
“We found that adults aged 20-49 are the main drivers of the COVID-19 epidemic in the United States and are the only age groups that contribute disproportionately to the spread, in relation to the size of their population,” said Dr. Melodie Monod of Imperial College.
“Although children and adolescents have contributed more to the spread of COVID-19 since school closure mandates were suspended in the fall of 2020, we found that this dynamic has not changed substantially since the school reopened,” she added.
Dr. Oliver Ratmann from the college said: “We believe this study is important because we have demonstrated that adults aged 20 to 49 are the only age groups that have consistently supported COVID-19 spread across the USA, despite wide variations in scale and time of local epidemics.
“Thus, at least where highly transmissible variants have not been established, additional interventions targeting the 20-49 age group can bring resurgent epidemics under control and prevent deaths,” he added.
Meanwhile, a new study suggests that antibodies against coronavirus last at least six months after infection for most people who have contracted the virus.
The UK Biobank survey found that 99 percent of participants who tested positive for previous infection retained antibodies for three months after infection, while 88 percent did so for the full six months of the study, according to Sky News.
“This important study revealed that the vast majority of people retain detectable antibodies for at least six months after infection with the coronavirus,” said Professor Naomi Allen, chief scientist at Biobank in the United Kingdom.
“Although we cannot be sure how it relates to immunity, the results suggest that people can be protected against subsequent infections for at least six months after the natural infection,” said Allen.
“Longer follow-up will allow us to determine how long this protection can last,” she added.