The University of Bristol’s Faculty of Health Sciences and the London School of Hygiene and Tropical Medicine's Research Ethics Committees provided approvals for the study (references: 99102 & 21887).
Two geographically distinct areas in England with historically lower uptake of the HPV vaccination programme were selected as research sites: Bristol local authority and the London Borough of Southwark. These sites were selected as they build on existing relationships between the immunisation and research teams and where there was drive to improve delivery of the vaccination programme.
Our target population groups were young men and women aged 12–15 years and key stakeholders (e.g. immunisation nurses, youth workers and school staff). The age group 12–15 years was selected as these young people were perceived to have diverse experiences in relation to having been offered the HPV vaccine through the programme.
Prior to funding being secured, preliminary discussions around participation were held in Bristol with two youth organisations. Following research permissions being granted, information about the study was also distributed by public health officials to managers of youth organisations within Southwark, London. One organisation responded to the invitation and agreed to take part. All three organisations work with young people with sociodemographic backgrounds that have been identified with lower uptake of the HPV vaccination programme [5, 6].
Young people were initially approached by a member of staff at the participating organisations and provided with written or electronic information about the study. Key stakeholders were identified through the research teams existing relationships with youth organisations, immunisation teams, and schools in the study areas. An additional interview was undertaken with a sex and relationships educator who was identified as the activities progressed.
INTERVENTION PLANNING AND DEVELOPMENT
We used the ‘person-based approach’ to intervention planning and development , which enabled us to develop an appropriate theory-, evidence-, and person-based framework to underpin the EDUCATE package. Incorporating the views of the target users (young people and professionals involved in delivery of the HPV vaccination programme) throughout the development, design, and testing processes increases the likelihood that the educational package will be acceptable, engaging, persuasive, and easy to use. In turn, this is intended to promote engagement, implementation and, ultimately, effectiveness .
The planning and development phases involved the following interrelated stages: (i) collating and analysing evidence; (ii) developing guiding principles; (iii) undertaking a behavioural analysis; (iv) development of a preliminary logic model; (v) co-production of the intervention, and; (vi) intervention refinement.
Further details on the methodology comprising each of these components are provided below.
(i) Intervention planning methodology: Collating and analysing evidence
The purpose of this stage was to collate primary and secondary evidence to understand behavioural issues that lead to lower HPV vaccination uptake in the target population groups, and the challenges of addressing these.
A review of the relevant literature
Key papers highlighting the relevant behavioural issues were collated. Additional handsearching of citations and reference lists supplemented the original documents identified.
Patient and public involvement
We consulted with members of the Bristol Young People’s Advisory Group (YPAG) (https://generationr.org.uk/bristol/) and Bristol City Youth Council (https://www.bristol.gov.uk/youth-council-youth-mayors) about the initial design of the study. The study manager (HF) also tested the initial prototype for the intervention by delivering HPV vaccine awareness raising sessions in two schools, one of which was delivered in collaboration with an immunisation nurse.
Members of the Bristol YPAG also provided feedback on participant information sheets and recruitment materials. Changes to the format of the documents were made according to their feedback to ensure the materials were more appealing to young people.
Content analysis of existing HPV vaccine communication materials for young people
To inform the initial stages of the planned research, we summarised existing HPV vaccine communication materials that targeted young people and were published in the English language. The methodological approach is reported in full elsewhere .
Preliminary interviews and workshops
The findings from the content analysis were used to inform topic guides to seek further feedback and clarification from young people (n=11) and key stakeholders (n=6) regarding appropriate content to include within the materials for the educational package. The key areas within the topic guides were: (i) knowledge about the HPV vaccine; (ii) views of existing communication materials; (iii) delivery of educational package, and; (iv) suggestions for content of materials. The topic guides are provided in Additional File 1.
Subsequently, a workshop plan was developed comprising activities where young people (n=11) at three youth organisations were asked to: (i) review existing communication materials identified through the content analysis; (ii) comment on their understanding of key HPV vaccine messages; (iii) make suggestions of their preferred messages, design, and language style, and; (iv) state their preferences for how the information should be delivered (e.g. in person by a healthcare professional, through media including animation). The workshop plan is provided in Additional File 2.
Interviews and workshops were digitally recorded and conducted by two researchers (HF & TC). These were facilitated through digital platforms because of public health guidance around the coronavirus disease (COVID-19) pandemic at the time. Research activities were undertaken one-to-one, or in pairs or small groups, to suit the needs and preferences of the participants.
Recordings of interviews and workshops were transcribed verbatim. Transcripts were anonymised and double checked for accuracy against the audio file. Thematic analysis  was undertaken assisted by the Framework approach to data management  within QSR NVivo software. We used both an inductive and deductive approach to analyse the content, focusing on our main research questions while identifying key issues emerging from the data. Coding of all transcripts was undertaken by one researcher (HF), while a second researcher (TC) double-coded a sub-set of the transcripts (n=6) to check for meaning, relevance, and reliability.
Consensus meetings (HF, TC) were undertaken to review, refine, and confirm the main themes and codes relevant to the developing content for the educational package. As the process of coding progressed and data were extracted, key terms and phrases were retained while repetition and extraneous text were removed (HF).
(ii) Intervention planning methodology: Guiding principles
In the ‘person-based approach’, the guiding principles comprise a design objective and intervention features that address the user/context-specific behavioural need, issue or challenge identified in the earlier planning stages. Provisional guiding principles were iteratively developed by the research team and refined as further understanding was gained throughout the study.
(iii) Intervention planning methodology: Behavioural analysis
The behavioural analysis aimed to identify behaviours to be targeted by the EDUCATE package and their potential barriers and facilitators. The Behaviour Change Wheel was selected as it was designed to help researchers link behaviours to inform intervention design. Identified behaviours were mapped onto constructs from the Behaviour Change Wheel  to clearly describe the intervention processes and components, including behavioural domains, intervention functions, and the Behaviour Change Techniques  to be targeted.
(iv) Intervention planning methodology: Logic model
In line with the 2021 framework for the development of complex intervention , a logic model was developed to provide a visual representation of the proposed mechanisms of change for the EDUCATE package. This brought together the findings from the intervention planning activities and how these are anticipated to improve uptake of the HPV vaccination programme.
(v) Co-production of the EDUCATE resources
The next stage of the research involved co-producing the content and format of the resources being developed. This involved collaborations between the study researchers, young people aged 12 to 15 years (n=16), an HPV-cancer survivor, an immunisation nurse, and the creative team at Knowle West Media Centre in Bristol (www.kwmc.org.uk), who are experienced in working with young people to create health-related media materials.
Researchers (HF & TC) developed preliminary plans outlining the content and suggested structure of the educational package, which was anticipated to comprise a PowerPoint presentation integrated with short films and Question-and-Answer breaks. A short training manual containing key information and frequently asked questions was also produced. Key stakeholders (members of an immunisation team, a secondary school teacher, and professional within immunisation operations for the national programme) reviewed and commented on the scripts for the videos and content of the PowerPoint presentation. This ensured the content was accurate, evidence-based, and consistent with best clinical and educational practice.
To create the content, three filming shoots were organised across the research sites at a secondary school, a youth organisation, and an HPV-related charity. Animations were subsequently developed to include content not captured through the filming shoots. Music demos to accompany the films and animations were produced by young people enrolled on the Future Creative Leaders scheme hosted by Knowle West Media Centre. Young people were asked to provide feedback on an initial story board developed by an animator and select the music to accompany each film.
(vi) Refinement of the EDUCATE resources
The EDUCATE package was provided to young people through a pre-recorded session delivered during tutor time in a secondary school (Bristol) and a session delivered in a youth organisation (Southwark, London). Young people (n=17) participated in small group interviews to provide their feedback. Topic guides were developed to elicit their perceptions of the positive and negative aspects of the educational package, including how it was delivered, the design, and suggesting or creating new content. The topic guides are provided in Additional File 1.
Further feedback on the content of the educational package was obtained through a series of workshops organised with key stakeholders (n=15) (members of immunisation teams in both the study sites, representative from the World Health Organisation), in addition to the co-authors of this manuscript.
Responses from all participants were collated in a Table of Changes document. Modifications to the educational resources were made in line with the ‘person-based approach’ common guiding principles  and the guiding principles developed specifically for the EDUCATE package. This considered whether they were likely to impact on behaviour change or a precursor to behaviour change (e.g. acceptability, feasibility, persuasiveness, motivation, engagement). Prioritisation for changes were based on the MoSCoW (Must have, Should have, Could have, Would like) criteria 
INTERVENTION PLANNING AND DEVELOPMENT ACTIVITIES
An overview of the results from the intervention planning and development activities are provided below.
(i) Intervention planning: Collating and analysing evidence
The literature review identified the key behavioural determinants for young people that contribute to inequalities in uptake of the English HPV vaccination programme. These include low levels of understanding about the HPV vaccine among some young people, fear of receiving the vaccine, and lack of autonomy by young people in decision-making and consent procedures (Table 1).
[Table 1. Evidence for key behavioural determinants that the EDUCATE package is trying to address]
Patient and Public Involvement
During advisory group discussions, young people reflected on their own information needs having been offered the vaccine in the school-setting. There was consensus that videos were an appealing way to communicate health-related information. There was no clear preference for who should deliver the educational package, as both teachers and healthcare professionals were valued.
Acceptability of the initial prototype was ascertained following preliminary feedback from young people who attended sessions where it was delivered. Young people’s questions during the session related both to the HPV vaccine and preparation for vaccination. Some young people appeared reassured that the immunisation nurse delivering the information session would be present at their upcoming vaccination session, and requested that they would personally administer the vaccination. At the request of one of the schools, the information session was delivered separately by gender. This appeared to allow young men to ask different questions specifically about HPV-related cancers affecting men.
Content analysis of existing communication materials
Overall, the communication materials identified encompassed varied formats and content, reflective of different HPV vaccination programmes and the priorities of the organisations responsible for producing the materials. For example, some communication materials presented information related to safety and side-effects in terms of how many people were anticipated to have the side-effects, whereas others only provided confirmation relating to safety or minimal side-effects with no explanatory information. Few communication materials addressed sexuality as a risk factor for HPV-related disease. We report further details of the findings elsewhere, in addition to how these were used to inform the subsequent stages of the research .
Preliminary interviews and workshops: Content and delivery of the educational package
Analysis of the data focussed on key issues relevant to intervention development. These were ‘delivery’ (support, gender, addressing training needs, and role of professionals) and ‘key content to be communicated’ (risk of developing cancer, safety and side-effects, sexuality and behaviours). A summary of the findings, and illustrative quotations that were expressed concisely and typify responses relating to the thaemes, are presented in Table 2.
[Table 2. Key themes from preliminary interviews and workshops]
(ii) Intervention planning: Guiding principles
In brief, the EDUCATE package aims to: (i) improve young people’s knowledge and understanding about the HPV vaccine; (ii) increase young people’s confidence to have a vaccine in the school setting; (iii) engage young people in the decision-making and the consent process, and; (iv) be delivered flexibly to meet the needs of the target population (Table 3).
[Table 3. Guiding principles for the EDUCATE package —an intervention to improve HPV vaccine uptake]
(iii) Intervention planning: Behavioural analysis
The proposed EDUCATE package employs four intervention functions (enablement, education, persuasion, and environmental restructuring) which are enacted by six behavioural change techniques (‘instruction on how to perform a behaviour’, ‘information about health consequences’, ‘anticipated regrets’, ‘generalisation of target behaviour’, ‘pros and cons’, and ‘restructuring the social environment’) (Table 4).
[Table 4. Behavioural analysis of EDUCATE intervention using the Behaviour Change Wheel and the Behaviour Change Technique]
(iv) Intervention planning: Logic model
The logic model for the EDUCATE is provided in Figure 1.
[Figure 1. Logic model for EDUCATE]
(v) Co-production of the EDUCATE resources
Building on our findings from the interview and workshop data with young people and key stakeholders, and the wider literature, the following key themes for content were selected: (i) HPV-related information; (ii) how vaccines work; (iii) safety and side-effects of vaccination; (iii) eligibility for the HPV vaccination programme, and; (iv) preparation of young people to receive the HPV vaccine . Signposting young people to other information sources, such as websites or professionals involved in the delivery of the programme, was also valued.
Film shoots were organised around the following scenarios confirmed by young people: (i) interview with young people post-vaccination around their experience of having the vaccine at school; (ii) unvaccinated young people interviewing vaccinated (older) young people; (iii) young people interviewing healthcare professionals to find out key information; (iv) a vaccination session taking place, and; (v) a case study with a person who has experienced HPV-related cancer.
An initial script and story board for an animation was developed to capture content not captured through the filming shoots (‘HPV-related information’ and ‘how vaccines work’). Feedback resulted in changes related to communicating messages around: the sexual transmissibility of HPV; ensuring imagery of young people were ethnically diverse, and; avoiding assumptions around HPV infection risk only affecting heterosexual partnerships.
(vi) Refinement of the EDUCATE resources
The resources for the EDUCATE package are PowerPoint slides, interspersed with five short films. A guidance document with additional information for the delivery of the session was also produced. We intend to make the final product available in the public domain shortly.
The creative team selected a colour palate and font that was intended to be appealing to young people. Overall, young people and key stakeholders were positive about the materials and felt they would be beneficial in helping young people find out about the HPV vaccine.
The changes enacted upon were mostly minor alterations to the content of the PowerPoint slides, such as changing words to improve clarity of meaning. In some cases, further content was added to the guidance document to balance providing additional information within the PowerPoint with overloading information at the risk of disengaging young people (e.g. availability of HPV vaccine for men-who-have-sex-with-men in sexual health and HIV clinics). Additional notes to assist delivery of the package were added to the PowerPoint slides. Design changes included the redesign of existing diagrams to match the overall style and ensuring gender balance of figures on the PowerPoint slides. The length of one of the films was also reduced to ensure the information was succinct.