Children, Adolescents More Vulnerable to Omicron Variants

Omicron variants are over five times more transmissible than the original strain of COVID-19 among children and adolescents, a study suggests. 

A team led by Chun June-young at the National Cancer Center and Kim Yong-dai at Seoul National University analyzed the severity of COVID infection by age group in three different periods -- from October to December 2020 before Delta variants were found in Korea, from June to August 2021 when Delta dominated, and in January this year when Omicron began spreading.

They found that the transmission rate among children aged 10-15 was 5.28 times higher after Omicron variants began spreading than before Delta variants were found. Among those aged 15-19 the transmission rate was nearly five times higher. 

But the rate only doubled among the over-50s and rose a mere 1.12 times among the over-75s. 

Omicron variants were nearly three times more transmissible than Delta variants among children aged 10-19, but a mere 0.93 times among the over-75s. 

Until recently, the presumption was that children with immature upper airways are more susceptible to Omicron variants, considering that the infection from Omicron variants occurs more easily in the upper airways than in the lungs. 

"It is important to vaccinate children," the team said.

The study was published in the international journal BMC Medicine last week.