Objectives: Influenza disease considered to be more sever and complicated in old age persons, because immune response diminish in this group. This disease is one of the main causes of mortality in elder people. The prevalence of influenza disease in elderly are living in nursing home is more in compare if they dwell in community. We studied the effect of influenza vaccine on the incidence and numbers of episodes of influenza like illness (ILI) and cost of cares in old population residing in Kahrizak Charity Foundation, during nine months period from December of 2004 Through September 2005.

Methods & Materials: This Cohort study was executed in the Kahrizak Charity Foundation, which is located in southwest of Tehran. Outcomes of residents whom were administrated influenza vaccine (n=389) and control subjects whom weren't administrated influenza vaccine (n=557), monitored clinically for onset of ILI and its relative drugs, radiology and laboratory costs. Range of participant's ages were 60-105 years.

Results: For intervention group one dose of inactivated, subunit trivalent influenza vaccine was administered. During December 2004 to September 2005, 10.9% of participants caught ILL There were statistically significant lower percents of ILI (7.2% in vaccinated group and 13.4% in unvaccinated control group). Lower of drugs, laboratory and total costs in vaccinated group in compare to unvaccinated group (Consequently 1174±4918, 48500±119362 and 90690±119962 in vaccinated group versus.2521±8710, 179494±408479 and 183015±43634 in unvaccinated control group. There wasn't significant difference in deaths between vaccinated group and unvaccinated control group (65 case in vaccinated group and 66 case in unvaccinated group and Odds ratio=1.04). No serious adverse reactions to vaccination were recorded. Thus, influenza vaccination is safe and effective in this population and should become a part of the routine care of old persons who are dwelling in nursing homes.

Conclusion: This study implicates clinical efficacy and cost- benefit of influenza vaccination in nursing home residents in Iran. Annual influenza vaccination of old people requires the attention of all nursing home attendants, physicians, and public health organizations.

Introduction: The most effective and practical strategy to maintain the health of the elderly against infectious diseases is prevention through vaccination, and despite the production of numerous vaccines around the world, the success of vaccination depends on its public acceptance. Despite the beneficial effects of vaccination in recent years, many advertisements from various groups in Iran have been against vaccination, which has targeted the elderly community in particular. The present study was designed with the aim of determining the validity and reliability of the Persian version of "Vaccination Attitude Tool (VAX)" in Iranian elderly.
Method: The present study was a methodological study and was conducted on 240 Persian-speaking elderly people who referred to health centers in Abadan city with available sampling . The data were analyzed using Cronbach's alpha, confirmatory factor analysis, content validity ratio and content validity index and using SPSS_22 and AMOS_22 software. 
Findings: The average age of the elderly was 67 years old, and 61.3% of the participants were male. The face and content validity of the questionnaire was confirmed, and the convergent validity between the VAX and Co-VASA questionnaires was reported with a Spearman correlation coefficient of -0.78. With confirmatory factor analysis, it was found that the 4 factors proposed by the instrument manufacturer are approved and the model obtained from these factors has a good fit.
The reliability of the questionnaire was also calculated and reported through Cronbach's alpha, internal consistency and inter-rater reliability of 0.89, 0.9 and 0.71, respectively.
Conclusion: The final form of the Persian version of the VAX instrument has 12 items, whose face and content validity is confirmed. The internal reliability coefficient and stability of this test are acceptable and excellent. Therefore, the Persian version of the VAX questionnaire can be used as a valid and reliable tool to determine the attitude of the elderly towards vaccination.