Determinants of MPOX Vaccine dropout in Approved Vaccination Centers in Rivers State, Nigeria

Abstract

Background: Mpox, formerly known as monkeypox, has emerged as a significant public health concern in Nigeria, particularly in the south-south region, with Rivers State identified as one of the states with confirmed cases. This study aimed to determine the Mpox vaccine dropout rate between the first and second doses, vaccine completion rate and identify factors associated with vaccine dropout in approved vaccination centers in Rivers State, Nigeria.

Methods: A descriptive cross-sectional study was conducted among 768 eligible individuals aged 18 years and above, comprising first-line health workers, immunocompromised individuals, and all persons who visited three approved vaccination centers between December 2024 and January 2025. Data was collected using a pretested, validated, interviewer-administered questionnaire and analyzed using descriptive and inferential statistics.

Results: Most participants were female (57.3%), within the 36-60 years age group, and 45.2% resided within a 5 km radius of a vaccination center. The study found a dropout rate of 44.3% (340 out of 768), which was statistically significant (χ² = 121.743. Factors significantly associated with dropout included older age, female sex, vaccination at the University of Port Harcourt Teaching Hospital (UPTH), and residing more than 5 km from the vaccination center. Multivariate analysis revealed that sex, vaccination site, and proximity to the center were independent predictors of MPOX vaccine dropout.

Conclusion: The high dropout rate emphasizes the need for targeted interventions to improve vaccine completion, such as ensuring consistent vaccine supply, decentralizing vaccination services, providing reminder systems, and offering flexible scheduling to enhance full vaccination coverage and reduce dropouts in future campaigns.