Background: Vaccine hesitancy is an important public health problem as it could prolong the
pandemic. Aim: To assess moderating effect of psychological antecedents and conspiracy mentality
on COVID-19 vaccine hesitancy among a sample of Egyptians. Design: Cross-sectional research
design was adopted during COVID-19 outbreak. Sample: Convenience sample of 1390 participants
were recruited through a web-based survey. Tools: Four tools were used for data collection:
Demographic and Medical Data questionnaire, Oxford COVID-19 Vaccine Hesitancy Scale,
Conspiracy Mentality Scale, and 5 Cs Psychological Antecedents of Vaccination Scale. Results:
About 45.3% reported vaccine hesitancy that was highly significantly correlated to conspiracy
beliefs. Confidence, complacency, constraints, and responsibility appeared as major psychological
factors that separates the vaccine acceptance group from the hesitancy group. Social media was the
main source of information about COVID-19 vaccine. About (59.2% & 38.5%) had moderate and
high conspiracy mentality respectively. Conclusion: Psychological factors and conspiracy beliefs
impacted vaccine hesitancy among participants. Recommendations: Educational programs should
be implemented to increase the awareness about the safety and efficacy of COVID-19 vaccines.