His mother is worried about community transmission, so he will stop going to school
His mother is worried about community transmission (of omicron), so
(男性の)生徒の母親が、市中感染のことを心配して、
市中感染=community transmission
he stopped going to school
学校に来なくなった
stopped~
~しなくなった
he will stop going to school
学校に来なくなる
ご参考になれば幸いです!