Paediatricians on Friday warned that an influx of kids hospitalised with respiratory infections has put children's wards at hospitals under strain, a day after health authorities said Hong Kong has entered the influenza season.

Louis Chan, the Hospital Authority Vice-chairman of the Coordinating Committee in Paediatrics, said the occupancy rate of public hospital beds for children often reached around 70 to 80 percent, and at times topped 100 percent.

He also said the number of children admitted to hospital after getting the flu had risen by over 40 percent in the past week.

"From our clinical observations, we've seen that respiratory samples from many children who were hospitalised contained more than one type of respiratory virus," Chan said.

"There is increasing evidence, especially from overseas studies, that the combination of Covid and influenza results in a higher chance of developing complications."

Patrick Ip, from the Department of Paediatrics and Adolescent Medicine at the University of Hong Kong, said there has been a significant increase in flu outbreaks at schools, adding that the number of severe influenza cases is also on the rise.

He told a Commercial Radio programme that the flu season this year peaked later than usual, possibly owing to strict Covid measures.

"The flu season has begun to peak. And we've observed that the vaccination rate for flu is still very low, especially for young children and the elderly. Therefore, during this period, parents should take preventive measures as soon as possible, including vaccination in the early stages of an outbreak to build up antibodies," Ip said.