Vaccination is the most cost-effective way to maintain population health. However, it can only be effective if widespread acceptance is held. The efficacy of COVID-19 vaccines depends on their favor. When countries start to vaccinate their citizens, there is a certain level of skepticism about the effectiveness of the vaccines. The hesitancy study on vaccines has gained momentum following the pandemic. However, few studies have examined the link between the psychological and sociodemographic factors influencing the fit. This paper proposes integrating the concepts of the information systems success and stimulus–organism–response into a cognitive fit theory framework to explore the integration of psychological and sociodemographic factors in the receivers’ reactions (n= 1510). This study analyses the factors that influence the hesitancy of vaccines and the public’s refusal in Asia and Europe. Receivers’ reactions were assessed to various stimuli and we explored the link between psychological and sociodemographic elements and the concept of fit. Two surveys were conducted following the scale development of Mackenzie. The first was to develop the fit scale, while the second was to validate the fit scale. The results of the second survey were analyzed using structural equation modelling. The results indicate that the scale’s fit development is valid and reliable. The quality of the vaccine information, the psychological characteristics of the vaccine system, and vaccine receivers’ satisfaction are also beneficial factors for emotional and cognitive fit. Maintaining the vaccines’ quality and efficiency can help improve the fit between sociodemographic and psychological characteristics. It can also enhance receivers’ satisfaction and encourage continued vaccine administration. This study is regarded as one of the first to examine and develop an emotional and cognitive fit scale for practitioners and researchers.