This study aims to provide evidence of hesitancy in receiving the COVID-19 booster vaccine and associated factors in the vaccinated population that have completed a primary vaccination series. An anonymous web-based survey was disseminated to Malaysian adults aged ≥18 years via social media platforms. A total of 1010 responses were collected, of which 43.0% (95%CI 39.9-46.0) declared a definite willingness to receive a COVID-19 vaccine booster, 38.2% (95%CI 35.2-44.3) reported being somewhat willing and only 5.7% (95%CI 4.5-7.4) reported being definitely unwilling. Demographically younger participants, those of higher income, Chinese ethnicity and those from the central region reported significantly higher odds of a definite willingness to receive the COVID-19 vaccine booster compared to the reference group (somewhat willing/undecided/somewhat unwilling/definitely unwilling). Having no side effects with past COVID-19 vaccination was associated with a significantly higher odds of definite willingness (OR = 2.82, 95% CI 1.33-5.99). A lower (range 6-22) pandemic fatigue score (OR = 2.34, 95% CI 1.75-3.22) and higher (range 24-30) preventive practices score (OR = 2.45, 95% CI 1.80-3.34) were also associated with higher odds of definite willingness. Regarding attitudes toward COVID-19 booster vaccine, having fewer concerns about the side effects of booster vaccination and the uncertain long-term safety of multiple COVID-19 vaccinations were found to create greater odds of a definite willingness to receive the COVID-19 vaccine booster. Findings from this study provided insights into demographic characteristics and important behavioral and attitudinal factors associated with COVID-19 vaccine booster hesitancy.
Keywords: COVID-19 vaccine booster acceptance; Malaysia; pandemic fatigue; side effects; vaccine hesitancy.