BEIJING -- China's health authorities on Tuesday stressed the important role of vaccination in disease control, urging the public to have their children vaccinated in a timely way.

Judging from queries received by the National Health and Family Planning Commission, some people are still confused or skeptical about vaccination in the wake of a scandal where a large quantity of improperly stored or expired vaccines have allegedly been sold across the country since 2011, said the commission's spokesman Mao Qun'an on Tuesday.

The immunization program is the most economic, effective and safest way of preventing, controlling and eradicating communicable diseases, Mao said, adding vaccination under the national immunization program has proved quite fruitful in the control of preventable diseases.

Since China introduced the immunization program in 1978, the rate of hepatitis B in children aged below five has been greatly reduced, and incidences of encephalitis B and epidemic cerebrospinal meningitis hit historical low.