The head of the Paediatric Society, Patrick Ip, on Saturday called on kindergartens to take measures to minimise the risk of Covid transmission, saying it is hard for younger children to wear masks during naps.

His comment came after officials reported on Friday a probable case of transmission in a kindergarten in Wan Chai. Two children who had slept close together were infected.

Ip, who's also an associate professor at the University of Hong Kong, said it was hard for younger children, whose respiratory systems have not matured, to sleep with their masks on.

He said kindergartens should do what they can to prevent Covid from spreading on campus.

"For example, when children need to remove their masks, they need to ensure that children will be kept at a certain distance... and also with some protection like having some plastic covers," he said.

He also called on parents to get their children vaccinated at the earliest opportunity, saying while around 74 percent of children aged between three and 11 had at least got their first jab, in some kindergartens and primary schools only around half of the pupils had been jabbed.

Ip said some wrongly believe that children who have recovered from the virus don't need to be vaccinated.

He said outreach vaccination programmes should be arranged for the pupils in their schools, adding that adults who come into contact with children should receive no fewer than three doses of the vaccine.