The results of this study reveal that while uptake of hepatitis B vaccination among health laboratory practitioners in Dar es Salaam shows progress compared to earlier Tanzanian and regional reports, uptake remains inadequate for full protection. The observed gaps in dose completion, coupled with structural barriers like vaccine unavailability and scheduling difficulties, highlight systemic weaknesses in occupational health programs. Interestingly, the counterintuitive association between strong belief in vaccine effectiveness and lower vaccination uptake suggests that access and programmatic issues, rather than knowledge deficits, may play a more decisive role in determining vaccination behavior.

In this study, the full-dose hepatitis B vaccine uptake among laboratory practitioners was 54.6%, which is relatively high compared to many reports from Tanzania and across Africa. A 2015 survey at Muhimbili National Hospital in Dar es Salaam reported 33.6% full vaccination and 56.9% with at least one dose, both lower than our estimate, suggesting gradual improvement over time [11]. More recent data from the same hospital in 2025 found 46.3% uptake, again slightly below our figure [18]. In contrast, a study from the Mwanza region reported only 18% of individuals were fully vaccinated, highlighting significant disparities between urban referral centers and peripheral facilities [6]. The high uptake in this study was due to the study’s focus on health laboratory practitioners in urban referral hospitals, who are routinely trained in biosafety and infection control. In contrast, other studies included broader HCWs, often with lower risk perception and weaker access to vaccination. Additionally, vaccination uptake may have increased over time due to national policies, heightened awareness of HBV, and occupational safety campaigns.

Regionally, the uptake in East Africa has historically been lower. For example, only 12.8% of Kenyan HCWs in a 2006 study had ever received the vaccine [19], and pooled estimates from Ethiopia place full-dose coverage at approximately 20%, with a recent survey of Addis Ababa nurses reporting 36.9% coverage [20,21]. In Uganda, mass vaccination campaigns achieved a 20% completion rate of the three-dose schedule, underscoring persistent challenges in community uptake [22]. Rwanda stands out as an exception: in a tertiary hospital cohort, nearly all participants who had initiated vaccination had completed all three doses, reflecting the impact of well-structured institutional programs [23].

At a broader continental level, a meta-analysis across Africa reported 24.7% full-dose coverage among HCWs, with the East African subgroup even lower at 15.1% [24]. Against this backdrop, our estimate of 54.6% uptake compares favorably, positioning our study population above both the national and regional averages. Nonetheless, coverage remains far from optimal, particularly in achieving universal protection, highlighting the need for more comprehensive Hepatitis B vaccination programs among healthcare workers in Tanzania.

Multivariable analysis revealed that two factors independently predicted hepatitis B vaccine uptake: work experience and perception of vaccine effectiveness. Healthcare workers with more than two years of service were significantly more likely to have been vaccinated compared with those with less than two years of experience, a finding consistent with other Tanzanian and regional studies that link longer occupational exposure to greater vaccination rates [6,11].

Interestingly, however, respondents who reported the vaccine as “very effective” or “slightly effective” were less likely to be vaccinated than those who responded, “don’t know.” This negative association contrasts with findings from Ethiopia and other African settings, where positive perceptions of vaccine effectiveness were generally associated with higher [24,23]. Globally, reviews also report that confidence in vaccine efficacy usually promotes uptake [26]. The divergence observed in our study may reflect contextual factors such as limited vaccine availability, programmatic barriers, or response bias, underscoring the need for qualitative inquiry to clarify how attitudes toward effectiveness translate into vaccination behavior in our setting.

The leading barriers to completing the hepatitis B vaccine series in our study were missed appointments (48.5%) and unavailability of vaccines at the workplace (41.9%). These findings are broadly consistent with a meta-analysis of African healthcare workers, in which 50.5% cited vaccine unavailability and 37.5% reported demanding work schedules as reasons for non-completion. In comparison, nearly half 50% had never been offered vaccination opportunities at all [24]. Tanzanian studies similarly highlight structural challenges, such as a lack of institutional vaccination programs and inconsistent vaccine supply, as major impediments [6,11]. Globally, systematic reviews concur with these findings, identifying poor access, limited workplace vaccination services, and weak reminder systems as recurring barriers to series completion among healthcare workers [26]. Collectively, this evidence highlights the importance of structured, facility-based immunization programs that ensure vaccine availability, integrate appointment reminders, and strengthen supply chain systems to enhance coverage and ensure completion of the full vaccine schedule.

This study provides valuable insight into hepatitis B vaccination coverage among laboratory practitioners in Dar es Salaam, contributing to the limited local data on occupational vaccine uptake. A key strength is the use of a structured data collection approach and verification of vaccination status, which enhances the accuracy of reported uptake. Additionally, including multiple hospitals improves the representativeness of the findings within the city’s healthcare setting. However, the use of convenience consecutive sampling within hospitals may introduce selection bias, potentially limiting the generalizability of the results.