Mind the Gap: Sex-Specific Drivers of Human Papillomavirus Vaccination Uptake in Serbian University Students

Despite proven effectiveness, human papillomavirus (HPV) vaccination uptake remains suboptimal in many countries. The aim of this study was to explore differences in beliefs about HPV and HPV vaccination, the information environment and social influences shaping vaccination decisions between male and female undergraduate university students in Belgrade, and to identify sex-specific factors associated with HPV vaccine uptake. A cross-sectional study was conducted between April and December 2024. An online questionnaire was completed by 1529 female and 423 male students who were either receiving their second or third dose of the nonavalent HPV vaccine, or accessing general healthcare services at the general medicine department of the Institute for Students' Health of Belgrade. Hierarchical logistic regression was used to identify predictors of HPV vaccine uptake in male and female students. Among female students, HPV vaccine uptake was associated with stronger beliefs in vaccine efficacy (OR = 2.01, 95% CI: 1.50-2.69) and safety (OR = 2.29, 95% CI: 1.69-3.10), lower perceived lack of information (OR = 0.71, 95% CI: 0.60-0.84), and social influence of family members, (OR = 1.45, 95% CI: 1.04-2.03), colleagues (OR = 1.62, 95% CI: 1.01-2.59) and media (OR = 1.92, CI: 1.10-3.37). Among male students, vaccine uptake was associated with stronger beliefs in vaccine efficacy (OR = 2.14, 95% CI: 1.37-3.34), lower perceived lack of information (OR = 0.71, 95% CI: 0.52-0.98), more frequent reliance on scientific literature (OR = 1.50, 95% CI: 1.15-1.97) and family (OR = 1.37, 95% CI: 1.07-1.75) and less frequent use of YouTube (OR = 0.70, CI: 0.53-0.92) as sources of information, and social influence of family (OR = 1.83, 95% CI: 1.03-3.24). This study highlights significant sex differences in factors influencing HPV vaccine uptake, indicating that tailored approach is required in designing vaccine promotion strategies. Strengthening communication on efficacy and safety, improving access to reliable information, and addressing sex-specific concerns such as safety and financial barriers in females and misinformation in males could improve uptake and equitable HPV protection.