CONSORT flow diagram of participants throughout the study.
The sample size was calculated according to the following equation: Sample size = (zThe standard deviations were considered to be δInclusion criteria were: consent to participate in the study, and completion of Internship 1.Exclusion criteria were: completion of the compulsory medical service program, and employment in the health system.The students in the intervention and control groups were evaluated in terms of Knowledge, self-efficacy and attitude before and immediately after the intervention. Their performance in the vaccination was also measured a month after the intervention was completed and before they started vaccination work in comprehensive health centers or health homes. The performance was determined by a checklist, which was completed by one of the researchers in both groups.