Introduction: Aside from personal beliefs, young adults’ intention to uptake the COVID-19 vaccine can be influenced by their fear of COVID-19 and perceived infectability of COVID-19. The present study incorporated fear of COVID-19 and perceived infectability with the theory of planned behavior (TPB) to form an expanded TPB to analyze factors affecting Pakistani young adults’ intentions to uptake the COVID-vaccine in Pakistan.

Methods: A cross-sectional study was conducted and recruited participants from Pakistani social media users. The proposed extended TPB model was examined by using structural equation modeling.

Results: A total of 1034 individuals replied to the survey. The three factors of the original theory of planned behavior and the fear of COVID-19 were positively related to their intention to uptake COVID-19 vaccination (r = 0.25-0.66). Moreover, the perceived infectability positively influenced the three theories of planned behavioral factors and the fear of COVID-19 (r = 0.27-0.60), also affecting the participants’ intentions to uptake COVID-19 vaccination.

Conclusions: Perceived infectability was positively related to the participants’ intentions to uptake COVID-19 vaccination, and perceived behavioral control was the strongest mediator. More evidence-based information concerning treatments and COVID-19 vaccination are needed to encourage individuals to uptake the vaccine.