the trend of the extended program of immunization (epi) in iran from the beginning (1984) to 2013

introduction the extended program of immunization (epi) in iran is started in 1984, and it played an important and effective role in controlling many infectious diseases in community. the objective of this study was to determine the time trends of vaccination coverage by the type of vaccine among children, in the age group of 0-24 months, in iran from the beginning of epi (1984) to 2013. materials and methods this study has been conducted as a descriptive analytical research to evaluate the vaccines of extended program of immunization in iran from 1984 to 2013. the data of this study have been obtained from the world health organization and unicef. the data of this study included the percentage of coverage for routine vaccines in iran national immunization program in children, aged 0-24 months. the data analysis has been done by stata, version12. results the coverage of all vaccines has been continuously increased from 1984 to 2013, and now the coverage for all of them is about 99 percent. all coefficients in the regression models are positive and statistically significant (p <0.05). birth dose of hepatitis b (hepbb) and third dose of diphtheria–tetanus–pertussis containing vaccine (dpt3) variables with coefficients of 1.52 and 1.34 had the highest rate of increasing during this period, respectively. the first dose of diphtheria–tetanus–pertussis containing vaccine (dpt1) with a coefficient of  0.65 had the lowest coefficient among other variables. conclusion according to the findings, maintaining the wide coverage, monitoring and updating the program can play an important role to improve children&apos;s health, contagious disease prevention, and health promotion.