Health officials have strengthened monitoring and management measures in the production and circulation process of the vaccine, he said, adding all staff have to be trained before they begin to provide measles vaccine injections.
China's vaccines have been used for a long time during routine measles vaccination and proved as an effective immune barrier against measles, said Peter Strebel of the WHO's Department of Immunization, Vaccines and Biologicals.
According to Health Ministry officials, China seeks to reduce the incidence rate of measles to below one in a million by the end of 2012.
Figures from the ministry show that a total of 52,000 measles cases were registered nationwide in 2009, down 60.1 percent from the 131,000 cases in 2008.
The incidence rate in 2009 was 39 per one million.
Since 2004, children in 27 regions across the country have been vaccinated against measles, with an average vaccination rate above 97 percent.
