Self-reported hepatitis B vaccination uptake and associated factors among adults in a tertiary hospital, Nasarawa State, Nigeria

Background Hepatitis B virus (HBV) infection remains a major public health challenge in sub-Saharan Africa despite the availability of a safe and effective vaccine. In Nigeria, adult vaccination coverage and completion rates are not well characterized within hospital-based populations. Methods A hospital-based cross-sectional study was conducted among 1,200 adults attending Federal Medical Centre (FMC) Keffi, Nasarawa State, Nigeria. Data on socio-demographics, HBV-related knowledge, attitudes, perceived barriers, vaccination uptake, and completion were collected using a structured questionnaire. Knowledge and attitude scores were categorized into poor, fair, and good levels. Associations between socio-demographic characteristics and vaccination uptake were examined using chi-square and Fisher’s exact tests, with statistical significance set at p < 0.05. Results The mean age of respondents was predominantly 36–40 years (32.5%), with males constituting 72.3%. Most respondents had tertiary education (91.8%) and were civil servants (83.4%). Overall awareness of HBV was high (95.5%), with a mean knowledge score of 12.37 ± 1.42. Good knowledge was observed in 74.2% of respondents, while 57.2% demonstrated good attitudes toward HBV prevention. Vaccination uptake was high, with 93.5% reporting receipt of at least one vaccine dose. However, only 22.3% had completed the recommended three-dose schedule, while 48.2% and 23.1% had received one and two doses, respectively. Willingness to complete vaccination was reported by 81.6% of respondents. Perceived barriers included high vaccine cost (72.4%), inadequate access to health facilities (96.9%), fear of side effects (71.9%), and insufficient information (73.5%). No significant associations were found between socio-demographic variables and vaccination uptake (p > 0.05 for all). Conclusion Despite high HBV vaccination initiation and knowledge levels, substantial gaps in vaccine completion persist. Addressing financial, informational, and access-related barriers is essential to improve full vaccination coverage among Nigerian adults.