This study demonstrates a high burden of missed opportunities for HPV vaccination in the Temeke Municipal Council, with more than seven in ten eligible adolescent girls failing to receive the vaccine despite accessing health services. The observed magnitude is concerning and underscores persistent weaknesses in opportunistic vaccination delivery in urban health facilities. Quantitative findings revealed that fewer than half of caregivers were offered HPV vaccination, while qualitative data highlighted poor integration of HPV services into routine care, limited screening during non-immunization visits, and fragmented documentation practices.

Comparable patterns have been reported in Sub-Saharan Africa (SSA) and other Tanzanian settings, where inadequate service integration and limited provider engagement contributed to missed opportunities exceeding 60% (10, 11, 21). In Kilimanjaro’s Hai District, uptake was estimated at 65%, constrained by misinformation and lack of sensitization (12), while the HPV-Plus program demonstrated that comprehensive health education could increase acceptance despite persistent hesitancy linked to inadequate caregiver involvement (18, 21). These parallels indicate that missed opportunities in Temeke reflect broader systemic challenges across urban Tanzania, underscoring the importance of improving service integration and provider engagement. In contrast, lower rates reported in Rwanda and Ethiopia (25–35%) have been attributed to strong school-based delivery models, integrated screening systems, and structured digital tracking tools (14, 22, 23). Conversely, in more resource-constrained contexts, such as Nigeria and Malawi, MO rates exceed 80%, largely due to stock-outs, weak infrastructure, and entrenched sociocultural resistance (24, 25). These comparisons suggest that Temeke’s high MO burden reflects modifiable system-level gaps rather than entrenched caregiver resistance.

Caregiver knowledge and perceptions emerged as important determinants of missed opportunities. Limited awareness and misconceptions, particularly the belief that HPV vaccination is only relevant for sexually active girls, were more common among caregivers with lower education levels. Similar findings have been documented in SSA at large and in other parts of Tanzania, such as in Kilimanjaro and in Ilala, Dar es Salaam (10, 11, 16). However, evidence from out-of-school and in-school-based programs in SSA suggests that delivery platforms that reduce reliance on caregiver initiative can mitigate the influence of HPV vaccination uptake (26).

On the supply side, provider failure to mention HPV vaccination during visits was the most frequently reported barrier, affecting 60% of missed cases. Stock-outs, uncertainty about eligibility, and weak referral mechanisms further compounded missed opportunities. These findings mirror challenges reported in Malawi and Nigeria (24, 25), but contrast with experiences from Ethiopia, where structured supervision and integrated workflows have minimized provider-related lapses (22).

Importantly, healthcare providers in Temeke articulated clear, feasible strategies to reduce missed opportunities, including routine eligibility screening at all service points, reminder systems, strengthened documentation, and enhanced community engagement. However, implementation was constrained by high workloads, limited staffing, inconsistent supervision, and supply chain interruptions. Addressing these operational barriers is critical to translating provider motivation into sustained improvements in vaccine delivery. Weak referral and follow-up systems further exacerbated missed opportunities, as few unvaccinated girls were directed to alternative service points. Taken together, these findings underscore that missed opportunities arise from a complex interplay between caregiver knowledge and motivation, provider practices, and systemic limitations.

These gaps reflect patterns similar to those seen in Kilimanjaro and elsewhere in SSA, where the lack of integrated screening contributed to frequent MOs (16, 26). In contrast, several SSA countries have embedded screening into routine workflows, thereby reducing reliance on provider memory (22, 23). Reminder tools such as appointment cards, short messaging services (SMS), and verbal prompts were also recommended and shown to be effective when applied consistently, and reminder systems improved vaccine completion (22, 23). However, concerns about unreliable mobile communication in low-income settings resonate with experiences in Sierra Leone (27), suggesting that reminder systems must be complemented with community-based follow-up. Community engagement through schools, community health workers, and religious leaders was highlighted as a powerful facilitator, consistent with evidence from Tanzania’s HPV-Plus program (21) and Rwanda’s sustained school and faith-based collaborations (26). Training and supportive supervision were also prioritized by providers, who emphasized the need for regular refresher courses on HPV guidelines and communication. However, inconsistent and often punitive supervisory practices in Temeke limited effectiveness, which may be improved by collaborative supervision. Overall, while providers expressed a strong commitment, operational challenges, such as high client volumes, limited staffing, stock-outs, and weak supervisory structures, constrained the systematic implementation of these strategies.

In conclusion, this study demonstrates that missed opportunities for HPV vaccination in Temeke Municipal Council are widespread and shaped by both demand- and supply-side factors, echoing challenges observed in other Tanzanian districts while also reflecting unique contextual dynamics. Compared with regional peers, Temeke’s rates are higher than those of Rwanda and Ethiopia (22, 26), where stronger system integration has minimized MOs, but lower than in some resource-constrained settings such as Nigeria, Malawi, and Sierra Leone (24, 25, 27). Importantly, caregiver acceptance and provider motivation remain relatively strong, suggesting that system-level interventions, particularly integration of routine screening, structured reminders, consistent supervision, and community engagement, could significantly improve uptake.

The strengths and limitations of this study merit mention. The mixed-methods design is a key strength of this study, enabling quantification of missed opportunities while providing contextual insights into underlying mechanisms. The inclusion of diverse facility types enhanced representativeness in the urban setting. However, the cross-sectional design limits causal inference, and reliance on self-reported data may have introduced recall and social desirability bias. The study’s focus on a single urban municipality limits generalizability to rural settings, and the exclusion of adolescent and community leader perspectives constrained deeper system-level analysis.

However, the findings highlight the need for national strategies that institutionalize provider training, improve logistics, and embed HPV vaccination into broader adolescent health packages, while simultaneously expanding school- and community-based outreach to counter misconceptions and reduce reliance on caregiver initiative. From a policy perspective, these results call for scaling up integrated digital tracking and reminder tools, strengthening supply chain management, and fostering continuous provider mentorship. For practice, they underscore the importance of empowering providers with tools and supportive supervision to integrate HPV vaccination into all service encounters. For research purposes, further evaluation of hybrid models that combine school-based delivery with opportunistic facility-based vaccination will be critical to optimizing coverage and sustainability. By addressing both structural and behavioral barriers, Tanzania can move closer to equitable HPV vaccination coverage and the reduction of cervical cancer risk among adolescent girls.