Compliance with Two Vaccination Regimens of Freeze-Dried Human Rabies Vaccine (Vero Cell) and Influencing Factors in Hubei Province, China

Objective: To systematically analyze the practical application and differences in vaccination compliance of two rabies post-exposure prophylaxis regimens based on real-world data, and to explore the associated influencing factors of vaccination compliance, aiming to provide evidence for optimizing vaccination strategies. Methods: Vaccination records of exposed individuals who received the freeze-dried human rabies vaccine (Vero cell) documented in the Hubei Provincial Immunization Information Management System from 1 January to 31 December 2024 were retrospectively collected to evaluate compliance with the five-dose (Essen) and four-dose (Zagreb) vaccination schedules. Good compliance was defined as completing the vaccination according to the schedule within the prescribed time frame. The evaluation included the vaccination compliance rate and the full-course vaccination rate. Factors associated with compliance were explored using univariate and multivariable analyses. Results: A total of 51,066 subjects were enrolled. The four-dose (Zagreb) schedule was associated with significantly higher vaccination compliance (77.1% vs. 72.0%, χ2 = 94.913, p < 0.05) and full-course completion rates (85.2% vs. 82.4%, χ2 = 38.251, p < 0.05), whereas the five-dose (Essen) regimen was associated with a higher rate of timely initial vaccination (81.7% vs. 78.1%, χ2 = 61.602, p < 0.05). In the multivariable analysis, the four-dose (Zagreb) regimen was also associated with increased full-course completion (aOR = 1.49, 95% CI = 1.39–1.60) and better compliance (aOR = 1.52, 95% CI = 1.43–1.61), whereas in a pre-specified, descriptive exploratory model, it was associated with delayed first doses (exploratory aOR = 0.84, 95% CI = 0.79–0.89); this adjusted association should not be interpreted as a causal effect of regimen on timely initiation. Younger age, lower-limb wounds, high-security occupations, farming, passive immunization and non-winter exposure were associated with better full-course vaccination; adults aged ≥18 years, males, Han/Miao ethnicity, Grade III exposure and cat bites were associated with lower compliance (p < 0.05). Severe exposure, farmer/student/resident identity, passive immunization and spring exposure were associated with more timely initiation, whereas male sex, neck-and-above exposure and flexible work were associated with less timely initiation (p < 0.05). Conclusions: In this retrospective, non-randomized study, receipt of the four-dose (Zagreb) regimen was associated with modestly higher full-course completion (absolute difference: 2.8 percentage points) and better compliance (5.1 percentage points) than the five-dose (Essen) regimen. Conversely, it was associated with a lower rate of timely first-dose vaccination. As an observational study, these findings do not establish causal relationships. Therefore, immediate wound care, prompt vaccination, and appropriate administration of rabies immunoglobulin remain the principal clinical priorities.