RESUMEN
BACKGROUND: Vaccine hesitancy has been around since the introduction of smallpox vaccine. Vaccine hesitancy has become more intense due to the rise of vaccine information in social media and mass adult vaccination during COVID-19 pandemic. This study investigated knowledge, perception, and reasons for rejection of the COVID-19 vaccine among Malaysian adults who refused to get free COVID-19 vaccination. METHODS: An online cross-sectional survey using an embedded mixed-method study [QUAN(quali)] was conducted among Malaysian adults. The quantitative section consisted of a 49-item questionnaire, whereas the qualitative sections consisted of two open-ended questions (1) "Please state your reason why you have not registered or have no intention to register at all for COVID-19 vaccines?" and (2) "Please tell us if you have any suggestions for improvement about COVID-19 vaccine delivery". Data from respondents who were not willing to get vaccination were extracted from the overall data and further analyzed in this paper. RESULT: Sixty-one adults completed the online open-ended survey with a mean age of 34.28 years (SD = 10.30). Among factors that influenced them to get vaccinated was information on vaccine effectiveness (39.3%), death due to COVID-19 (37.7%), and recommendations from the Ministry of Health (36.1%). Most of the respondents (77.0%) were knowledgeable about vaccines, with half having high-perceived risks (52.5%) to COVID-19. While 55.7% and 52.5% had, high perceived barriers and benefits to COVID-19 vaccines respectively. The reasons for vaccine rejections included vaccine safety, indecisiveness, underlying medical conditions, herd immunity, non-transparent data, and use of traditional or complementary medicine. CONCLUSION: The study explored the multitude factors that drive perception, acceptance, and rejection. The qualitative approach with a small sample size provided more data point for interpretations and allowed participants to express themselves. This is important to develop strategies to create public awareness on vaccines not just for COVID-19 but any infectious diseases that can be curbed through vaccination.