April 26 (UPI) -- Young children are at a low risk for COVID-19 and do not play a "substantial" role in virus spread while attending school, though the same cannot be said for adolescents and teens, a study published Monday by JAMA Network Open found.
In the analysis of coronavirus risks before and after the reopening of schools in Israel last fall, children age 9 and younger had a 10% higher likelihood for becoming infected after they returned to class compared to the period immediately beforehand, the data showed.
Those age 10 to 19 had a three-fold higher risk for infection after returning to school compared to when they still were at home, according to researchers.
"Our results suggest that unless there is a general lockdown, school was relatively safe for [young] children ... provided that preventive measures have been implemented," study co-author Dr. Eli Somekh told UPI in an email.
"Children are more likely to contract COVID-19 from infected family members rather than from other children in school settings," said Somekh, a professor of pediatrics at Mayanei Hayeshua Medical Center in Bnei Brak, Israel.
Many countries around the world, and most regions in the United States, opted to close schools soon after the start of the COVID-19 pandemic in March 2020 as part of efforts to contain spread of the virus.
However, as researchers began to learn more about the coronavirus and how it passes from person-to-person, policies regarding in-person learning, particularly for young children, began to evolve.
In February, the U.S. Centers for Disease Control and Prevention revised its COVID-19 guidelines to recommend that schools could reopen, even in areas with high virus spread, provided they implemented "mitigation" strategies, including mask-wearing and social distancing measures.
The changes were made because young people age 5 to 17 account for fewer than 10% of all COVID-19 cases nationally, and that children are not considered major drivers of disease spread, CDC officials said at the time.
Data released by the agency later that month also suggested that teacher-to-teacher and teacher-to-student transmission accounted for nearly half of all in-school cases.
For this study, Somekh and his colleagues analyzed data on 47,620 children up to age 9; 101,304 youths 10 to 19 years old; and about 320,000 adults 20 years old and older in Israel, all of whom tested positive for COVID-19 between late August and December.
Coronavirus case rates were compared among all age groups for the week before schools reopened Sept. 1 through two weeks later, and again for the last week of October, when schools were closed again due to a surge in cases across the country, and after students returned to class in November and December.
Compared with the period before reopening, children ages 9 years old and younger had a 10% higher risk for infection. Young people age 10 to 19, as well as adults age 20 and older, had up to a three-fold higher risk for infection.
This suggests that the risk for infection, and spread, was far higher in the community at large than in grade schools, according to the researchers.
"School attendance was not a major driver for COVID-19 spread in children attending school nor for COVID-19 resurgence among the community, during the study period," Somekh said.
However, "the situation is dynamic, and some ... variants may spread more efficiently in children," he said.