The top health authority is considering whether to further expand the national immunization program to protect children from more types of infection.

The move was disclosed by Yu Wenzhou, a senior specialist with the National Immunization Program under the Chinese Center for Disease Control and Prevention, during an online interview staged by the National Health and Family Planning Commission.

Wednesday's interview was to mark National Child Vaccination Awareness Day, which falls on April 25 each year.

"Vaccines for chickenpox and HIB (Haemophilus influenza type b) will probably be added to the current list of 14 vaccines under the national program," Yu said.

The two vaccines are currently among those that health departments recommend, he said. But recipients must pay for them.

Yu said various factors, including the disease burden, efficacy of a vaccine, the nation's financial situation and the cost/effect ratio, have to be considered when deciding on the types of vaccine under the national immunization program.