China on Tuesday stressed the importance of getting immunized against the flu as the country enters its annual flu season from December to January next year.

Wu Jiang, director of the immunity department of the Beijing Municipal Center for Disease Control and Prevention, said children under five years old and the elderly people most needed to get the flu jab.

Babies and children from six months to three years old were a high-risk group, said Wu, noting that the vaccination was the most effective way to prevent getting the seasonal flu.

A report of the World Health Organization (WHO) showed that one third of the world's elderly population catch the flu every year.