RESUMO
INTRODUCTION: The main aim of this study is to evaluate the effectiveness of preventive actions regarding influenza in the studied populations. The secondary objective is to analyze and understand the mechanisms which bring about a behavioural change regarding influenza vaccination. METHODS: The interventional and prospective study was undertaken in the form of an anonymous questionnaire about influenza vaccination coverage and about the reasons for vaccinating or not vaccinating. The studied populations were patients followed for cystic fibrosis (n=67) in the Dunkerque cystic fibrosis treatment centre and their health care workers (n=117), before (April 2014) and after (April 2015) an information campaign and primary prevention actions (vaccination in the workplace with expanded time slots) in collaboration with the department of occupational medicine. RESULTS: In 2015, the vaccination coverage rate of health care workers rose to 65.63%, that is to say 2.38 times more than in 2014 (27.55%). This difference is significant (χ2[1]=29.17, P<0.0001). However, no significant difference between 2014 and 2015 was observed among patients (children and adults) (χ2[1]=0.24, NS) whose vaccination coverage was already optimal before the study. CONCLUSIONS: Raising awareness among health care workers about vaccination against influenza increases the coverage rate and decreases outbreaks of virus infection in the care services and among patients at risk. Three main levers were identified: the necessity of providing information on influenza vaccination to health care workers, the ease of vaccination access and the attitude towards vaccination of supervisory staff (health executives/doctors).