This report is part of series aiming to capture the perspectives of a diverse group of health practitioners working to deliver or manage immunization services in low- and middle-income countries. Contributing to consultative engagement between international and local levels, each report offers a unique opportunity to discover unfiltered experiences and insights from thousands of people whose daily lives revolve around delivering immunization services. A total of 6185 healthcare workers wishing to take part in the IA2030-focused peer learning programme run by the Geneva Learning Foundation (TGLF) in 2022 completed an online application form, part of which asked them to identify the most difficult and important challenge they faced. Responses provided by the first 2000 applicants (1000 English-speaking, 1000 French-speaking) were mapped onto IA2030 strategic priority and key focus areas. For the most popular key focus areas, responses were subcategorized to provide more granular insights into the nature of priority challenges as perceived by applicants. Key findings Reported challenges most commonly fell into the following four IA2030 key areas of focus: 2.5 Knowledge (used to capture all challenges related to community demand and hesitation) 1.4 Supply chain 3.1 Reaching disadvantaged populations, particularly remote rural communities 1.3 Human resources Demand and hesitation challenges were by far the mostly commonly cited, accounting for around a quarter of all the challenges referenced. More granular coding identified lack of knowledge or understanding of vaccination’s benefits (or actions to address these issues) as the aspect of hesitation and demand thought to be most significant. In particular, hesitancy was identified as a major factor affecting COVID-19 vaccination, with myths and misperceptions seen to be having a major impact on take up. Conclusions An analysis of the key challenges identified by 2000 immunization programme staff from low- and middle-income countries has identified widespread concerns about low levels of demand and substantial vaccine hesitancy in communities. The causes of this hesitancy are frequently perceived to be limited knowledge or understanding of the benefits of vaccination. At the global level, recent years have seen growing emphasis on social and behavioural drivers of immunization-related behaviours as key factors in vaccination take up, including the development of a WHO position paper on understanding the behavioural and social drivers of vaccine uptake published in May 2022. Lack of knowledge is not included in the core framework of this position paper, given the lack of evidence that this is a significant factor in low take up. These findings therefore suggest a mismatch between global approaches to demand/hesitancy and the perceptions and actions of country-level practitioners in low- and middle-income countries, which focus primarily on closing perceived gaps in knowledge. The results do not imply that lack of knowledge is truly the biggest demand-related challenge in low-resource settings, and consultation with caregivers and communities could reveal a different picture. However, the findings do provide insight into health workers’ perceptions, which will be critical in shaping their choice of response. The results highlight the need for further investigation of demand-related attitudes among practitioners, and how these affect local demand-creation strategies, as well as of knowledge, attitudes and behaviour of caretakers in low-resource settings. Given the relative lack of data, they also emphasize the need for further work on the design of appropriate demand-creation approaches in low-resource settings, particularly given the potential impacts of COVID-19-related hesitancy on take up of essential immunization services. This Immunization Agenda 2030 (IA2030) case study is part of the IA2030 Movement’s Knowledge-to-Action Hub. Learn more about the Hub… Learn more about the Movement…