"Globally, measles is a leading cause of childhood morbidity and mortality.Although reported coverage for routine measles vaccination in Bhutan is high,substantial number of children remains unprotected due to various reasons.Measles vaccination does not confer 100 % protection. Sero -conversion rate with one dose of measles vaccination given at 9 months of age is only 85 %.Bhutan has a policy of administering second dose of measles to all children at the age of 24 months with expected protection of 95%.Supplementary activities like measles catch up campaign is required to sustain high measles vaccination coverage and for providing a second opportunity to the unvaccinated children and adults.This campaign is aimed at reducing the immunity gap in the susceptible population which was accumulated over the years and further supports measles elimination target for 2018." (page 3 and 4, Guideline for Measles and Rubella Catch Up (Supplementary ) Immunization Campaign in High Risk Areas 2017) Health Assistant of Tsakaling Gewog vaccinated the children of my school.