Background: EPI is one of the most cost-effective public health interventions that have already been identified. Mass vaccination is one of the most effective public health strategies that lead to a dramatic reduction in the incidence of many infectious diseases. This is a descriptive study (ecological exploratory) where data about the status of routine immunization of children under 6 years in 6 selected countries in terms of the routine immunization programs in each country, the coverage and reported cases of vaccine-preventable diseases from 2006 to 2008 were collected assuming that each country is a representative of a Continent; data about the status of Iran were also collected and a comparative study was performed in the next step. It is worth mentioning that selecting these countries was according to health experts to consolidate the data. Collection tools are data of international (WHO and UNICEF) and national organizations of the above countries. In all countries surveyed, triple vaccine, vaccines of polio, hepatitis B, measles, rubella and mumps are part of the routine immunization program for children under the age of 6 years, with the explanation that in South Africa only measles vaccine is injected instead of measles, rubella and mumps vaccines. The coverage rate of the vaccine and other vaccines in Iran was the best compared to other countries. This represents the widespread activity of health care systems of the country in the field of vaccination and tireless efforts of healthcare workers and health centers.
