Celebrated in the last week of April, World Immunization Week (April 24 - 30) aims to promote the use of vaccines to protect people of all ages against disease. Immunisation saves millions of lives every year and is widely recognised as one of the world’s most successful and cost-effective health interventions. Yet, there are still nearly 20 million unvaccinated and under-vaccinated children in the world today, says the World Health Organization. The theme of this year’s campaign is Protected Together: Vaccines Work!, and the campaign will celebrate Vaccine Heroes from around the world — from parents and community members to health workers and innovators — who help ensure we are all protected, at all ages, through the power of vaccines. Immunisation prevents illness, disability and death from diseases including cervical cancer, diphtheria, hepatitis B, measles and mumps.