Cambodian Ministry of Health on Monday announced the introduction of a new vaccine into the national immunization schedule to protect children against two viruses -- measles and rubella -- in a single dose. The biggest nationwide immunization campaign in the country\'s history which aims to vaccinate over 4 million children aged nine months to 15 years started Monday, said a joint press statement from the World Health Organization-Cambodia and the Ministry of Health. The campaign will be rolled out in every village, commune and district in three phases through the months of October, November and December, the statement said. Many immunization posts will be located in schools in close coordination with local government departments and the Ministries of Health and Education. Cambodia has made great progress in eliminating measles thanks to high coverage in a series of successful national measles vaccination campaigns, it said, adding that there are no cases of measles detected since Nov. 2011. \"This nationwide campaign will protect Cambodia\'s gains in measles elimination, while also protecting children from future rubella infection and the severe consequences of congenital rubella syndrome,\"the statement said. Rubella outbreaks, which occur every few years in Cambodia, can have long-lasting consequences for babies born with congenital rubella syndrome (CRS) that leads to blindness, deafness and heart disease. The WHO estimates that up to 260 children are born with CRS every year in Cambodia, with the number of cases rising to 1,400 during outbreaks. At the official launch of the campaign in Phnom Penh on Monday, Minister of Health Mam Bunheng said\"With the introduction of the rubella vaccine by the National Immunization Program combined with the campaign to vaccinate all children up to 15 years, no child will be susceptible to rubella when they become an adult and are ready to start their own families.\" \"It is important that this new measles-rubella vaccine reaches every child, especially those living in high risk, urban poor, remote and rural communities and ethnic and migrant populations,\" he said. Teams of national supervisors and international observers will follow the campaign and check that every child is reached especially in marginalized communities in rural and urban areas, said WHO Representative in Cambodia Pieter Van Maaren. \"There is every reason to be confident that this campaign and the introduction of the new measles-rubella vaccine will be successful,\"he said.