Omicron cases in children rise sharply

The Yomiuri Shimbun
A child is examined at Hosaka Kodomo Clinic in Bunkyo Ward, Tokyo on Jan. 19.

There has been a sharp increase in reported cases of the omicron variant of the novel coronavirus in children in Japan and abroad. Although the symptoms are said to be less severe, experts warn that omicron should not be taken lightly.

According to the American Academy of Pediatrics, the number of children up to ages 14 to 20 — the definition of children varies across states — infected in the United States increased 69% to about 980,000 in the seven-day period between Jan. 7 and Jan. 13 from the previous week.

In Britain, the number of new hospital admissions of children 5 or younger surpassed 30 per day early this month, about triple the figure in the year-end. The number of new cases among youths age 19 or younger in Tokyo was 2,296 on Sunday, up 287-fold from eight on Jan. 1. The pace of increase is twice as fast as the increase in all generations.

The omicron variant is said to be three to five times as infectious as the delta variant, according to research by the University of Tokyo and others.

In the United States, the vaccination rate for the 5-11 age group was only about 15% early this month, and it is believed to be one of the reasons for the spread of infection among children. In Japan, vaccination of 5- to 11-year-olds is scheduled to start in March, and it is believed that many children are not yet immune.

The omicron variant seems to cause fewer severe cases in children as well as adults. Animal experiments have shown that it is more likely to increase in the nose and throat and less likely in the lungs than the delta variant.

According to reports by universities in the United States and other organizations, the number of children 5 or younger sent to intensive care units within three days after infection with the omicron variant was only about 30% of that with the delta variant.

In rare cases, children with severe symptoms similar to those of Kawasaki disease have been reported two to six weeks after infection with the novel coronavirus in the United States and Europe, though the frequency of such symptoms with the omicron variant is still unknown.