Uptake and Determinants of Hepatitis B Vaccination among Health Laboratory Practitioners in Tertiary Hospitals in Dar es Salaam, Tanzania: A Cross-Sectional Study.

Hepatitis B virus (HBV) infection is a significant occupational risk for laboratory practitioners. Despite proven vaccine effectiveness and global recommendations, HBV vaccine uptake among healthcare workers in Tanzania remains low. This study assessed HBV vaccination uptake and its determinants among laboratory practitioners in tertiary hospitals in Dar es Salaam. An analytical cross-sectional study was conducted from March to June 2025 across four tertiary hospitals, enrolling 130 participants using the Kish-Leslie formula. Data were collected using a structured, pre-tested, interviewer-administered questionnaire and verified vaccination records, and analyzed with IBM SPSS v27. Descriptive statistics summarized participant characteristics, and associations were assessed using chi-square, Fishers exact tests, and Poisson regression with robust variance. Of 130 participants (median age 30 years, IQR: 25-36), 54.6% (71/130) completed the three-dose hepatitis B vaccination schedule, 23.8% (31/130) received partial doses, and 21.5% (28/130) were unvaccinated. Among the partially vaccinated, missed appointments (48.4%, 15/31) and lack of vaccine availability (41.9%, 13/31) were the main reasons. Half of the unvaccinated (50.0%, 14/28) cited lack of opportunity. Most participants knew the vaccine is essential (99.2%, 129/130), and 94.1% (96/102) acknowledged three doses are required for full protection. Participants with >2 years of work experience were nearly twice as likely to be vaccinated (aPR = 1.998, 95% CI: 1.064-3.173, p = 0.031). Those perceiving the vaccine as very or slightly effective were 44.8% (aPR = 0.552, 95% CI: 0.417-0.731, p = 0.010) and 41.9% (aPR = 0.384, 95% CI: 0.384-0.879, p < 0.001) less likely, respectively, to be vaccinated compared to those uncertain. HBV vaccine uptake among laboratory practitioners in Dar es Salaam is suboptimal, mainly due to structural barriers. Strengthening workplace vaccination programs, ensuring consistent vaccine supply, and implementing reminder systems could improve healthcare worker protection.