Factors associated with vaccination status among Korean submariners who are eligible for free non-mandatory influenza vaccination

Introduction: Submarine crews live in a confined setting and are vulnerable to influenza. Thus, it would be useful to identify factors that are associated with influenza vaccination. In this study, we investigated the influenza vaccination rate and the influence of health beliefs on the vaccination rate among submariners who were eligible for a free but non-mandatory vaccination program.

Methods: A total of 487 Korean submariners participated in this study after the closing of a free influenza vaccination program in 2015. Data regarding the participants' general characteristics and health beliefs (based on the health belief model [HBM]) were collected using a self-administered questionnaire, and their vaccination status was determined using their medical records. Multiple logistic regression analysis were performed to evaluate the associations of the HBM components with influenza vaccination.

Results: The overall vaccination rate was 78% (921/1183). The unvaccinated and vaccinated respondents exhibited similar characteristics, although the vaccinated group was significantly more likely to have high-risk family members (chronic disease, age of <2years, or age of ⩾65years; p=0.025). Among the HBM components, perceived severity (odds ratio: 1.38, p=0.019) and cue to action (odds ratio: 1.74, p=0.002) were significantly associated with a higher likelihood of influenza vaccination.

Conclusion: Vaccination policies that emphasize the severity of influenza and prompt individuals to undergo vaccination are needed to increase the vaccination rate among people who live in confined environments or institutions with non-mandatory vaccination programs.