Assessing the determinants of influenza and COVID-19 vaccine co-administration decisions in the elderly.

This research examines the low rate of co-administration of influenza and COVID-19 vaccines among seniors aged 65 and older in Korea, despite recommendations from authorities and academia worldwide. The study aimed to understand the influence of general characteristics and health beliefs on the vaccination choices of seniors, who were categorized into four groups based on their vaccination status: influenza only, COVID-19 only, both, or neither. A total of 400 participants, aged 65 and above, were selected through proportional stratified random sampling from five major Korean regions for a survey conducted between November 24th and December 15th, 2023. The results indicated no significant differences in general characteristics across these groups. However, regarding the health beliefs showed significant differences in perceived susceptibility and self-efficacy between the influenza-only and co-administration groups. Higher levels of perceived susceptibility and self-efficacy were associated with choosing co-administration. Contrary to previous studies focusing on safety concerns as a primary factor in vaccine hesitancy, this study highlights the role of individual health-related beliefs, particularly perceived susceptibility and self-efficacy, as critical in influencing the decision for co-administration among the elderly in Korea.