Integrated service delivery to improve adolescent health and human papillomavirus (HPV) vaccination in Lao PDR: a quasi-experimental mixed-methods study – study protocol

Abstract

Introduction

The Lao People’s Democratic Republic (PDR) faces the significant public health challenges of high cervical cancer incidence and suboptimal human papillomavirus (HPV) vaccine coverage alongside broader adolescent health concerns such as high adolescent pregnancy rates and inadequate sexual and reproductive health (SRH) literacy. This study protocol outlines an approach to address these interconnected issues comprehensively by evaluating an integrated service delivery model.

Methods and analysis

This study employed a quasi-experimental design with mixed methods to assess the impact of an integrated service package comprising HPV vaccination and improved adolescent health services in two districts of Louangnamtha province in Lao PDR. The study population included girls aged 10–13 years for HPV vaccination and boys and girls aged 10–13 years for other adolescent health services. The intervention district received this integrated service package delivered through school-based, facility-based and outreach approaches. The comparison district continued with its standard HPV vaccination and routine adolescent health service delivery, which does not include the additional refresher training, comprehensive sexuality education or dedicated SRH outreach services provided in the intervention district.

The intervention period was 7 months, from November 2024 to May 2025. Quantitative data on HPV vaccine uptake, SRH knowledge and attitudes and utilisation of adolescent health services were collected at baseline, midline (at 3 months) and endline (at 7 months). Qualitative data on barriers and facilitators to implementation, provider workload and capacity, and stakeholder perceptions were collected through in-depth interviews and focus group discussions with adolescents, caregivers, healthcare providers, educators, community leaders and policymakers at endline.

Ethics and dissemination

Ethical approval for the study has been received from the University of Health Sciences Research Ethics Committee in Laos (ID: 833/REC, dated 4 September 2024). Informed consent was obtained from all participants or their legal guardians. Findings will be disseminated through academic publications, policy briefs, workshops and community engagement activities to inform policies and practices in Lao PDR and contribute to the global knowledge base on integrated service delivery models.

Trial registration number

NCT06650956.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• A mixed-methods, quasi-experimental design was used to pragmatically evaluate a complex multicomponent intervention within a real-world setting.

• Evaluating a multicomponent service package against standard care prevented the attribution of observed effects to individual intervention components.

• The purposive selection of only two districts in Louangnamtha province limited the broader representativeness of the study sample.

• The exclusion of schools with fewer than 100 students for logistical feasibility introduced potential selection bias by underrepresenting remote populations.

• The reliance on self-reported data for assessing sexual and reproductive health knowledge and attitudes introduced potential recall and social desirability biases.

Introduction

The Lao People’s Democratic Republic (PDR) faces significant health challenges, including a high incidence of cervical cancer, which remains the second leading cause of death due to neoplasms among females aged 15–49.^{1 2} Despite the availability of prophylactic human papillomavirus (HPV) vaccines, national HPV vaccination coverage remains suboptimal, with the 2023 national average at 17.3% for HPV1 coverage.³ This is compounded by broader adolescent health concerns, such as the highest adolescent pregnancy rate in Southeast Asia and inadequate sexual and reproductive health (SRH) literacy.^{4 5} The WHO advocates for increased HPV vaccination coverage and quality to accelerate the elimination of cervical cancer, particularly in low- and middle-income countries such as Laos where screening programmes are limited.⁶

The national HPV1 coverage of 17.3% in Lao PDR is comparable to or slightly higher than the rates seen in some neighbouring countries. For instance, in 2023, only 12% of women and girls aged 15–29 in Vietnam had received the HPV vaccine.⁷ This regional data illustrates a shared public health challenge where national programmes are struggling to achieve high coverage. On an international scale, Lao PDR’s coverage rate is aligned with the average for Gavi-supported countries. In 2023, the HPV vaccine coverage in the 57 lower-income countries supported by Gavi was an average of 16%, a figure to which Lao PDR’s 17.3% coverage is quite similar.⁸ Despite these relative comparisons, all of these rates fall dramatically short of the ambitious global targets set for cervical cancer elimination. The WHO’s Global Strategy to Accelerate the Elimination of Cervical Cancer sets a key target of achieving 90% HPV vaccination coverage for girls by age 15 by 2030.⁶ The significant gap between Lao PDR’s current 17.3% coverage and this global target highlights the urgent need for innovative, effective and scalable interventions to improve vaccine uptake and protect the health of adolescent girls across the country.

Rationale for integrated service package

The integration of HPV vaccination with adolescent health services is a strategic and necessary approach to address these complex and interconnected health needs of adolescents in Lao PDR, aligning with national health priorities and international recommendations.⁹ This multicomponent service package was designed to significantly increase HPV vaccine uptake by offering the vaccine alongside other essential health services, such as SRH and rights (SRHR) education and counselling, thereby reaching a larger number of adolescents, especially in rural areas where healthcare access may be limited. This integrated approach is also expected to improve broader adolescent health outcomes by providing comprehensive SRH services, leading to reductions in unintended pregnancies and sexually transmitted infections (STIs). Furthermore, it aims to address social and cultural factors that contribute to poor adolescent health outcomes by fostering a safe and supportive environment that builds trust and rapport. The design of this integrated intervention was notably influenced by the social ecological model, which recognises the interconnectedness of individual, interpersonal, organisational, community and policy-level factors in shaping health behaviours and outcomes, aiming to maximise reach and efficiency through existing education and healthcare infrastructure. This integrated approach is also a cost-effective way to deliver essential health services, leveraging existing infrastructure and potentially leading to long-term cost savings from cervical cancer prevention.

Contribution to the evidence base

While integrated health service delivery models have shown success in other contexts, this study is specifically needed to assess the effectiveness of such a multicomponent service package in the unique context of Lao PDR. This study protocol aims to provide critical evidence on the overall impact of this integrated intervention, rather than isolating the effect of ‘integration’ alone, acknowledging the multifaceted nature of the intervention package. It will evaluate the effects of the integrated service package on HPV vaccine uptake, SRH knowledge and attitudes (KA), utilisation of adolescent health services, healthcare providers’ perceived workload and capacity, and stakeholder perceptions. The findings will inform policies and practices related to HPV vaccination and adolescent health service delivery in Lao PDR, contributing to the global body of knowledge on integrated service delivery models and potentially influencing similar interventions in other countries with low HPV vaccination coverage and limited access to adolescent health services.

Study objectives and research questions

The overall objective of this study protocol is to determine the effectiveness of an integrated service delivery package (comprising HPV vaccination and enhanced adolescent health services) in increasing HPV vaccine coverage equitably and sustainably, as well as contributing to selected adolescent health outcomes in Lao PDR. This study pursued the following specific objectives, attempting to answer relevant research questions:

1. To evaluate the effectiveness of an integrated service delivery package (comprising HPV vaccination and enhanced adolescent health services) on HPV vaccine uptake among 10-13-year-old girls in the intervention district compared to the comparison district over 7 months.

   • RQ 1.1: What is the difference-in-differences (DID) in HPV vaccine uptake between districts receiving the integrated service package and those receiving standard services over 7 months?

   • RQ 1.2: What factors contribute to the differences—if any—in HPV vaccine uptake between the district receiving the integrated service package and the district receiving standard HPV vaccination and routine adolescent health service delivery?

2. To assess the impact of the integrated intervention on adolescents’ KA related to SRH among 10–13 years old boys and girls, as well as their utilisation of other adolescent health services.

   • RQ 2.1: How does the integrated service package affect 10–13 years old adolescents’ KA related to SRHR in the intervention district compared to routine services in the comparison district over 7 months?

   • RQ 2.2: What changes in the utilisation of adolescent health services are observed among 10–13 years old in the intervention district, which receives the integrated service package, compared to the comparison district, which receives routine services?

3. To identify barriers and facilitators to implementing the integrated intervention in the Laotian context, including its impact on healthcare providers’ perceived workload and capacity.

   • RQ 3.1: What are the main barriers and facilitators to implementing the integrated intervention in the Lao context?

   • RQ 3.2: How does the integrated intervention impact healthcare providers’ perceived workload and capacity in the intervention district?

4. To explore the perceptions of adolescents, caregivers, healthcare providers and other stakeholders regarding the integrated intervention, including its perceived benefits and challenges.

   • RQ 4.1: What are the perceptions of adolescents, caregivers, healthcare providers, educators and other key stakeholders regarding the benefits and challenges of the integrated intervention?

   • RQ 4.2: How do the perceived benefits and challenges of the integrated intervention vary among different stakeholder groups?

5. To determine the costs and effects of integrating HPV vaccination with adolescent health services compared to delivering HPV vaccination alone and assess the cost-effectiveness of the integrated intervention in the Laotian context.

   • RQ 5.1: What are the costs and effects of integrating HPV vaccination with adolescent health services compared to delivering HPV vaccination alone?

   • RQ 5.2: How does the cost-effectiveness of the integrated intervention compare to that of delivering HPV vaccination alone in the Lao context?

Purpose statement

This protocol paper is published to provide a comprehensive and transparent outline of our research, adhering to established guidelines for study protocols. Its publication aims to keep researchers and funding bodies informed, prevent unnecessary duplication of work, and foster potential collaborations, thereby enhancing transparency in the research process and facilitating a clear understanding of the study’s design and any future deviations from this plan.

Methods

Study design

This study employed a quasi-experimental design with a convergent parallel mixed-methods approach to assess the impact of an integrated service delivery package comprising HPV vaccination and enhanced adolescent health services in Lao PDR. A quasi-experimental design was appropriate as random assignment of participants to intervention and comparison groups is not feasible in this implementation setting. The intervention model was a parallel assignment, where one group received the integrated service package and the other group receives standard services. To prevent bias, outcome assessors were masked, meaning they did not know which group received the intervention. The mixed-methods approach allowed for an in-depth understanding of the quantitative impact of the intervention on HPV vaccine uptake and other health outcomes, as well as the qualitative aspects of feasibility, acceptability and barriers/facilitators to implementation.

Study settings

The study was conducted in two districts of Louangnamtha province in Lao PDR: one intervention district and one comparison district. The selection of the intervention district was influenced by its lower HPV vaccine coverage within the province, the existing availability of adolescent health services and the willingness of local authorities and healthcare providers to participate. The comparison district was selected based on similar characteristics to ensure comparability. The comparison district continued with its standard HPV vaccination (targeting 10-year-old girls) and routine adolescent health service delivery, which may not include the same level of integration or the full range of SRHR services offered in the intervention district.

As shown in figure 1, HPV1 vaccination coverage among 10–17 years old girls in Laos in 2023 varies by province, with Bolikhamxai leading at 27.6% and Bokeo trailing at 12%. The national average stands at 17.3%. While Louangnamtha’s 12.3% coverage exceeds the lowest rates, it remains below the national average, suggesting a need for targeted efforts to improve vaccine uptake in this region and reach the goal of preventing cervical cancer.³

Figure 1. HPV1 coverage by province. Laos, 2023 (bar chart showing coverage rates across provinces, with Louangnamtha at 12.3% and the national average at 17.3%). HPV, human papillomavirus.

Cumulatively from 2020 to 2023, nearly 60% of 10–17 years old girls cohorts have completed two doses of HPV vaccine. Starting from 2024, Laos switched to a single-dose HPV vaccination strategy targeting 10–13 years old adolescent girls. It is important to note that the nearly 60% cumulative coverage refers to the proportion of 10–17 years old girls who have completed two doses of the HPV vaccine over the entire period from 2020 to 2023, whereas these provincial figures represent the single HPV1 dose coverage specifically for the year 2023. Both sets of coverage data are derived from the National Immunisation Programme’s (NIP) administrative records.^{3 10}

Louangnamtha province has achieved good progress in reproductive health, with high rates of modern contraceptive use and demand for family planning satisfied. This suggests a positive environment for integrating HPV vaccination with existing reproductive health services. Child nutrition indicators have also improved, particularly in reducing underweight prevalence, indicating a potential opportunity to leverage child health services for HPV vaccine delivery. However, immunisation coverage has slightly declined, and disparities exist in hepatitis B birth dose coverage compared with BCG, highlighting the need for targeted interventions to improve vaccine uptake, especially among specific populations and geographical areas.¹¹

The study was conducted in two districts within Louangnamtha province: Sing (intervention) and Viengphoukha (comparison). These districts were purposively preassigned by the research team in consultation with local health authorities based on the following criteria:

• Investigator convenience: The research team’s familiarity with these districts facilitates logistical arrangements and coordination.

• Lower HPV vaccine coverage: Both districts exhibit relatively lower HPV vaccination rates, aligning with the study’s aim to assess the impact of the integrated intervention in areas with greater need for improvement.

• SRHR programme opportunities: The districts present promising opportunities for integrating HPV vaccination with existing SRHprogrammes, enhancing the potential for successful implementation and impact.

Study population

Service users

• HPV vaccination (relevant to SO-1): The primary target population for the HPV vaccine was 10-year-old girls residing in the selected districts. The age range of 10–13 years is set to allow operational flexibility in a context where vital registries are weak and missed opportunities for vaccination are prevalent as indicated in anecdotal reports. This population group was studied to determine the extent to which the integrated service package increased HPV vaccine uptake among those in the intervention district compared with the comparison district over 7 months. The study focused on girls for HPV vaccination as it aligns with the national HPV vaccination programme targeting adolescent girls to prevent cervical cancer. The central justification for this targeted approach is the national HPV immunisation programme’s primary objective: to reduce the incidence and mortality of cervical cancer, noting its high burden and the WHO’s goal to accelerate the elimination of cervical cancer.⁶ Given that cervical cancer is a disease that affects women, the most direct and efficient pathway to achieving this goal is to vaccinate the at-risk female population. The decision to limit vaccination to girls was a pragmatic trade-off. While the benefits of gender-neutral vaccination—such as preventing HPV-related cancers in men and contributing to herd immunity—are well-documented, a resource-constrained programme must prioritise its most urgent and deadly threat.¹² By concentrating the high-cost vaccination resource on the population most directly and severely affected by the target disease, the programme maximises its chances of achieving its primary, policy-level goal in the most efficient manner possible.

• Adolescent health services (relevant to SO-2 and SO-4): The target population for the other adolescent health services included both boys and girls aged 10–13 years residing in the selected districts. This population was studied to measure the effect of the integrated intervention on adolescents’ KA related to their SRH. They served as key informants for the study to explore their perceptions regarding the integrated intervention, including its perceived benefits and challenges. In-depth interviews (IDIs) and focus group discussions (FGDs) were conducted to capture these insights.

• Inclusion criteria

The inclusion criteria for the study were as follows:

• Females aged 10–13 years who were eligible for HPV vaccination and received SRH education (relevant to SO-1, SO-2).

• Males aged 10–13 years who received SRH education (relevant to SO-2).

• Male and female students aged 10–13 years enrolled in randomly selected schools in the target classes—year 5 primary and year 1, 2 and 3 secondary.

• Out-of-school males and females aged 10–13 years living in two remote villages within the catchment area of each of four randomly selected health centres (HCs) located near the selected schools.

• Exclusion criteria

The exclusion criterion for the study is as follows:

• Males and females younger than 10 years or older than 13 years.

Service providers (relevant to SO-3 and SO-4)

• Front-line healthcare providers: Front-line healthcare providers including primary and community health cadres who provided the integrated service package were important informants for the study. Their insights were crucial for identifying barriers and facilitators to implementing the integrated intervention, including its impact on healthcare providers’ perceived workload and capacity. Interviews and FGDs were conducted to gather qualitative data on these aspects.

• School teachers: Primary school teachers who teamed up with front-line healthcare providers in providing comprehensive sexuality education (CSE) played a pivotal role in contributing their observations and opinions towards understanding how the intervention is designed, implemented as well as for improvement.

Stakeholders (relevant to SO-4)

• Caregivers or guardians: Caregivers or guardians of adolescents were invited to participate in the study to share their perceptions regarding the integrated intervention, including its perceived benefits and challenges. IDIs and FGDs were conducted to capture these insights.

• Community leaders: It was important to understand their views on the integrated intervention and its impact on the community. Their perceptions were gathered through qualitative methods to identify common themes and differences across stakeholder groups.

• Policymakers and programme managers were involved in interviews and FGDs to provide insights into the feasibility, acceptability and potential policy implications of the integrated intervention.

Sample and sampling

Sample and sampling matrix: quantitative and qualitative approaches

The sample and sampling strategies for both the quantitative and qualitative approaches are summarised in table 1.

Table 1. Sample and sampling matrix.

RQ	Outcome measures	Data tool	Sample	Sampling	Timing
1.1	Difference-in-differences of HPV vaccination rates	Primary data: surveys (I&C)¶	10–13 years old girls enrolled in-school	Two-stage cluster randomised surveys (school → girls).	Baseline, midline, endline
1.2	Factors		10–13 years old girls not enrolled in-school	Two-stage cluster randomised surveys (health centre → village → girls).
2.1	SRHR knowledge and attitudes	Primary data: surveys (I&C)¶	10–13 years old boys and girls* enrolled in-school (*The same samples from RQ 1.1 will be used as the female component of this sample.)	Two-stage cluster randomised surveys (school → boys and girls).	Baseline, midline, endline
			10–13 years old boys and girls* not enrolled in-school (*The same samples from RQ 1.1 will be used as the female component of this sample.)	Two-stage cluster randomised surveys (school → village → boys and girls).
2.2	Service utilisation	Secondary data: health facility records (I&C)¶	10–13 years old boys and girls* (*Data will be collected from health facilities on service utilisation by both genders in the target age group.)	Health facilities in the intervention district.	Baseline, midline, endline
3.1	Barriers and facilitators assessment	FGDs (I)¶	Healthcare providers, educators, community leaders	Total 9–12 FGDs (3–4 per category), with stratification by group (eg, separate FGDs for providers, teachers and community leaders) to ensure depth of discussion within peer groups and prevent power dynamics from inhibiting open conversation.	Endline
3.2	Provider perceived workload and capacity assessment	FGDs (I)¶	Healthcare providers* (*Same samples as for RQ 3.1, specifically targeting healthcare providers.)		Endline
4.1	Stakeholder perception	IDIs (I)¶	Adolescents, caregivers, healthcare providers, educators, policymakers	Total 25–30 IDIs across all categories. Approximately five IDIs per stakeholder category. Specific purposive sampling strategies will be employed for each group to ensure diverse and relevant insights.	Endline

C, comparison district; FGDs, focus group discussions; HPV, human papillomavirus; ¶ I, intervention district; IDIs, in-depth interviews; RQ, research question; SRHR, sexual and reproductive health and rights.

Sample size for quantitative approach

The study involved young adolescent girls and boys aged 10–13 years old, both in-school and out of school. The sample size was determined using the formula for proportional studies in a quasi-experimental design, with a design effect of 2 to account for sampling methods other than simple random sampling. The sample size for boys was equal to that of girls.

The formula used is as follows: $n=\frac{N{Z}^{2}P(1-P)}{e^2(N-1)+Z^{2}P(1-P)}\times D$

Where: n=number of required samples,

N=known number of study population,

Z=level of confidence at 95% (with a value of 1.96 for alpha 0.05),

e=precision of event measurement (or margin of error),

P=prevalence or proportion of event,

D=design effect.

The prevalence of HPV1 vaccination coverage in Louangnamtha province (P=12.3%) and the total number of girls aged 10–13 years old (N=3364) was used for the calculation.

$${\displaystyle {\displaystyle \begin{array}{r}n=\frac{3364\times {1.96}^2\times 0.123\times (1-0.123)}{{0.05}^2\times (3364-1)+{1.96}^2\times 0.123\times (1-0.123)}\times 2=318\times 110\mathrm{\%}\approx 350.\end{array}}}$$

The estimated sample size for girls is 350, including a 10% buffer. The sample size for boys was equal to that of girls (350). The total sample size for both intervention and comparison sites was 700 girls and boys aged 10–13 years old. This sample size was calculated to be sufficient to detect statistically significant differences in HPV vaccine uptake and SRHR KA between the intervention and comparison districts. Furthermore, this number of participants was deemed adequate to identify changes that are clinically meaningful for improving adolescent health outcomes and to provide robust evidence that can inform policy decisions regarding integrated health service delivery in Lao PDR, aligning with the pragmatic aims of this study to offer actionable findings for health systems planners and funders.

Sampling for quantitative approach

The study involved two districts (Sing and Viengphoukha) in Louangnamtha province, preassigned as intervention and comparison districts. The sampling strategy targeted year 5 primary school and year 1 secondary school students, with 40% of the sample (140 students: 70 girls, 70 boys) from year 5 and 50% (175 students: 88 girls, 87 boys) from year 1. The remaining 10% (35 students: 18 girls, 17 boys) was out-of-school adolescents, potentially missed by school vaccination programmes.

The sampling strategy involved the following steps:

• School selection: In the intervention district (Sing), there are a total of 76 primary and 10 secondary schools. From this list, four primary schools and four secondary schools were randomly selected to participate in the study using computer-generated random numbers via Microsoft Excel software. Similarly, in the comparison district (Viengphoukha), there are a total of 46 primary and 10 secondary schools. From this list, four primary and four secondary schools were again randomly selected using computer-generated random numbers via Microsoft Excel software.

• School adolescents recruitment: Within each selected school, two lists were created: one for girls and one for boys aged 10–13 years. Each student on these lists was assigned an ID number. A sex-stratified systematic sampling approach, proportional to the size of each list, was employed to select participants. The sampling interval was calculated as the total number of students on the list divided by the desired sample size. The first participant was randomly selected, and subsequent participants were chosen based on the sampling interval until the desired sample size is reached. Informed consent was obtained from selected students and their parents/guardians before conducting structured interviews.

• Out-of-school adolescents recruitment: Out-of-school adolescents, who may have missed school-based vaccination opportunities, were recruited through purposive sampling. The process began by randomly selecting four HCs located near the eligible schools in each district. Within each HC’s catchment area, two villages from zones 2 and 3 (mobile and outreach zones) were selected based on the highest number of girls missing vaccination or out of school. Village health volunteers and HC chiefs assisted in identifying and recruiting eligible girls and boys within these villages. All identified out-of-school adolescents within the selected villages were recruited for the study.

Sample size and sampling for qualitative approach

The qualitative sampling in this study employed a combination of purposive sampling strategies to recruit participants who possess the necessary knowledge and experience to provide valuable insights.

• Healthcare providers and educators: We used criterion sampling to select individuals who have been directly involved in delivering the integrated service package or CSE sessions. The selection prioritised those with diverse roles and experiences in providing adolescent health services and HPV vaccination.

• Community leaders and policymakers: We used expert sampling to select individuals with specialised knowledge of local health systems, policy implications and community dynamics. The selection prioritised leaders who can provide insights into cultural factors and potential barriers or facilitators to the intervention’s success.

• Adolescents and caregivers: For adolescents, the selection aimed for diversity in terms of gender, socio-economic background and experiences with the intervention. For caregivers, we began with criterion sampling (eg, caregivers of eligible adolescents) and used snowball sampling to identify other relevant community members, especially those whose daughter missed the previous HPV vaccination or whose daughter was vaccinated at age 12 or above.

The recruitment process involved providing potential participants with information about the study’s purpose, procedures and potential benefits and risks. Informed consent was obtained from all participants or their legal guardians before interview and before audio recording. The research team ensured that participants understood their rights, including the right to withdraw from the study at any time without penalty.

The recruitment process involved providing potential participants with information about the study’s purpose, procedures and potential benefits and risks. Informed consent was obtained from all participants or their legal guardians before interview and before audio recording. The research team ensured that participants understood their rights, including the right to withdraw from the study at any time without penalty.

The qualitative data collection involved conducting an estimated 10–12 FGDs and 25–30 IDIs. The estimated 25–30 IDIs were distributed across stakeholder groups, with approximately 5 IDIs for adolescents, 5 for caregivers, 5 for healthcare providers, 5 for educators and 5 for policymakers. For FGDs, we stratified by group (eg, separate FGDs for providers, teachers and community leaders) to ensure depth of discussion within peer groups and prevent power dynamics from inhibiting open conversation.

The principle of thematic saturation guided the determination of the final number of interviews and discussions. We employed a saturation grid to prospectively track the emergence of new themes within each stakeholder category. If saturation was not achieved within a group after the initial interviews, we conducted additional interviews as needed beyond the initial estimates.

Study procedures

To answer the research questions, a mixed-methods approach was employed, using quantitative followed by qualitative data collection and analysis techniques. The overall data collection process was overseen by VV for quantitative data and ST for qualitative data, as detailed in the Authors’ contributions section.

Quantitative data

• HPV vaccine uptake (research question 1.1): To assess the impact of the integrated intervention on HPV vaccine uptake, vaccination coverage rates among 10–13 years old girls in both the intervention and comparison districts were measured at baseline, at the 3rd month (midline) and at the end of the intervention (7th month). Primary data were collected from the study population of adolescent girls’ cohorts aged 10–13 years through interviewer-administered surveys (online supplemental appendix A—HPV Vaccine Uptake Survey Tool). Administrative data from immunisation registries and health facility records were used to triangulate the vaccination coverage.

• KA surveys (research question 2.1): To evaluate the impact of the integrated intervention on adolescents’ KA related to SRHR, KA surveys were administered to a representative sample of 10–13 years old boys and girls in both the intervention and comparison districts at baseline and endline. The survey tools (online supplemental appendix B—Knowledge and Attitudes Survey Tool) were carefully designed and were pretested to ensure age-appropriateness, cultural sensitivity and validity. This included careful consideration of questions related to sensitive topics, which were framed appropriately for the age group. The surveys were interviewer-administered to facilitate understanding and reduce literacy barriers.

  To ensure the appropriateness and clarity of the interviewer-administered questionnaire for adolescents aged 10–13 years, particularly concerning sensitive topics such as sexual development and risk behaviours, the questionnaire was pretested with a small, representative group of adolescents from outside the study districts prior to full data collection. This pretesting specifically evaluated the practicality and comprehension of the 5-point Likert scales used for attitude assessment, ensuring that 10 years old can reliably interpret and respond to these scales. This helped confirm comprehension of the questions, including those related to sexual intercourse and HPV vaccine knowledge, and evaluate the practicality of the Likert scales for this age group.

• Utilisation of adolescent health services (research question 2.2): To examine changes in the utilisation of other adolescent health services (eg, number of visits for counselling, education, contraception and disease prevention and management), data on service utilisation were collected from health facilities in both districts at baseline and endline. Baseline utilisation data were collected retrospectively for the preceding 6 months to establish a comparable period with the endline data, aiming to minimise recall bias by focusing on distinct health facility records (online supplemental appendix C—Health Facility Record Form).

Qualitative data

• Barriers and facilitators (research question 3.1): To identify barriers and facilitators to implementation (research question 3.2), IDIs and FGDs were conducted with healthcare providers, educators, community leaders and other key stakeholders involved in the intervention.

• Provider perceived workload and capacity (research question 3.2): To assess the impact of the integrated intervention on healthcare providers’ perceived workload and capacity, interviews and FGDs were conducted with healthcare providers in the intervention district.

• Perceptions of stakeholders (research questions 4.1 and 4.2): To explore the perceptions of adolescents, caregivers, healthcare providers, educators and other stakeholders regarding the integrated intervention, IDIs and FGDs were conducted with representatives from each group. Interview guides (online supplemental appendix D), IDI guides (online supplemental appendix E) and FGD guides (online supplemental appendix F) have been developed for each stakeholder group.

Intervention

The intervention was an integrated service package comprised of HPV vaccination and adolescent health services in the intervention district, delivered through multiple touchpoints from November 2024 to May 2025. The design of this multilevel integrated approach is informed by evidence from successful interventions in other settings, such as Togo’s experience integrating health education with HPV vaccination.⁹ The integrated service package was delivered through three primary touchpoints—school-based, health facility based and outreach, drawing on evidence from various studies that have shown the effectiveness of multicomponent interventions.¹³

School-based service delivery

• HPV vaccination: Girls aged 10–13 years received the HPV vaccine at school in the last week of November 2024. A vaccination campaign was conducted in primary schools to promote HPV vaccination and other relevant vaccinations for girls. The campaign used HPV vaccine promotion materials from the Lao Ministry of Health.

• CSE: A refresher training was provided to service providers of CSE, that is, teachers in schools. Teacher’s training manual on CSE was used, covering topics such as puberty, menstrual hygiene, STIs, HPV, vaccination, cervical cancer, healthy relationships, risk behaviours and self-protection. A 2-day to 3-day long training took place in September 2024. Materials for references were the International Technical Guidance on Sexuality Education (UNESCO 2018), Girl’s Project training manual, Vientiane Youth Centre (VYC) outreach manual, presentation slides and posters about HPV infection and vaccine.

• CSE sessions were delivered to primary school students aged 10–13 years. The sessions covered a range of SRHR topics and were conducted once every 3 weeks for a total of 10–12 sessions in the school year from November 2024 to May 2025. CSE sessions covered a broad range of SRHR topics including puberty, menstrual hygiene, STIs, HPV, vaccination, cervical cancer, healthy relationships, risk behaviours and self-protection. Interactive activities, using existing and appropriate photos, short videos and a student-based approach, were used to conduct CSE sessions by trained teachers in target primary schools. The sessions were aided by relevant audio-visual learning contents.

• Follow-up: The site project coordinator joined CSE sessions in schools monthly to monitor progress.

Facility-based service delivery

• HPV vaccination: Girls aged 10–13 years received the HPV vaccine at health facilities during regular clinic hours. This occurred throughout the months from November 2024 to May 2025.

• SRHR services: Healthcare providers received refresher training on HPV vaccination, SRHR-relevant services, adolescent and youth-friendly services, and counselling skills. The training used the National Adolescent and Youth Friendly Service Guidelines, VYC outreach manual and posters about HPV infection and vaccine. Health facilities provided a full range of SRHR services, including education, counselling, contraception and disease prevention and management. They used the National Adolescent and Youth Friendly Service Guidelines, posters about HPV infection and vaccine, worksheets, record sheets and report formats.

• Follow-up: The site project coordinator visited health facilities monthly to monitor the provision of service in the intervention package.

Community outreach

• HPV vaccination: Girls aged 10–13 years received the HPV vaccine through community outreach campaigns. This occurred quarterly from November 2024 to May 2025.

• SRHR promotion and service delivery: SRHR promotion messages and HPV vaccines were delivered to out-of-school girls through existing community outreach activities. This occurred quarterly from the third quarter of 2024 to the second quarter of 2025. The outreach used the VYC outreach manual, HPV infection and vaccine messages and posters.

• Follow-up: The site project coordinator visited during outreach sessions quarterly to monitor progress.

Standard HPV vaccination (comparison district)

• In the comparison district, routine HPV vaccination services were provided to girls aged 10–13. A school-based vaccination campaign was conducted in November 2024 to promote and administer the HPV vaccine. Additionally, the vaccine was available at health facilities starting in November 2024. Outreach activities were conducted to ensure access to the vaccine for hard-to-reach populations and out-of-school girls.

• Unlike the intervention district, there was no additional training for healthcare providers on CSE or other SRH services, and there were no dedicated community outreach sessions on SRH topics.

Participant timeline

The study was expected to begin participant recruitment in November 2024 and complete recruitment by May 2025. Data collection was estimated to start in November 2024, with the primary completion date, that is, final data collection date for the primary outcome measure, expected in May 2025. The study completion date was estimated to be in May 2025 (see figure 2).

Figure 2. SPIRIT schedule of study stages of enrolment, intervention, outcome assessment. (Diagram detailing the time points for enrolment, school-based/facility-based interventions and assessments at baseline, m1–m7 and close-out). HPV, human papillomavirus; m, month; SPIRIT, Standard Protocol Items: Recommendations for Interventional Trials; SRH, sexual and reproductive health.

Outcome measures

The primary outcome is the DID in HPV vaccine uptake among girls. Secondary outcomes include changes in SRH knowledge/attitudes, service utilisation and qualitative themes regarding barriers, workload and stakeholder perceptions (see online supplemental table 1 for the detailed description of all Outcome Measures).

Data analysis

To answer the research questions, a mixed-methods approach will be employed, using both quantitative and qualitative data collection and analysis techniques.

Quantitative data

• HPV vaccine uptake (research question 1.1): To assess the impact of the integrated intervention on HPV vaccine uptake (research question 1.1), a DID analysis will be employed to estimate the causal effect of the intervention, comparing the change in vaccination rates in the intervention district to the change in rates in the comparison district over the 7-month period, helping to control for any pre-existing differences between the two districts and isolate the impact of the intervention. The McNemar χ² statistic will be used for determining if there has been a significant change in vaccine uptake.

• The plan for the DID analysis can be outlined as follows:

Data preparation:

1. Outcome variable: The primary outcome variable will be a binary indicator of whether a girl aged 10–13 has received the HPV vaccine (1=vaccinated, 0=not vaccinated). The data for this variable will be collected at baseline, 3rd month and endline in both the intervention and comparison districts.

2. Treatment variable: The treatment variable will be a binary indicator of whether a girl resides in the intervention district (1=intervention, 0=comparison).

3. Time variable: The time variable will be a binary indicator of whether the data was collected at endline (1=endline, 0=baseline or third month).

4. Covariates: The analysis will include relevant covariates that could potentially influence HPV vaccine uptake, such as age, socio-economic status, education level and access to healthcare. The selection of covariates will be based on existing literature and data availability.

DID Regression Model:

The core of the DID analysis will involve estimating the following regression model:

$${\displaystyle {\displaystyle \begin{array}{rl}{Y}_{it}=& {\beta }_0+{\beta }_1{\mathrm{T}\mathrm{r}\mathrm{e}\mathrm{a}\mathrm{t}\mathrm{m}\mathrm{e}\mathrm{n}\mathrm{t}}_i+{\beta }_2{\mathrm{T}\mathrm{i}\mathrm{m}\mathrm{e}}_t\\ +{\beta }_3\left({\mathrm{T}\mathrm{r}\mathrm{e}\mathrm{a}\mathrm{t}\mathrm{m}\mathrm{e}\mathrm{n}\mathrm{t}}_i\times {\mathrm{T}\mathrm{i}\mathrm{m}\mathrm{e}}_t\right)+X_{it}\gamma +{\epsilon }_{it}\end{array}}}$$

Where:

• $Y_{it}$ = the outcome variable (HPV vaccination status) for individual i at time t.

• ${Treatment}_i$ = the treatment variable indicating whether individual i is in the intervention or comparison district.

• ${Time}_t$ = the time variable indicating whether the observation is at baseline, midline or endline.

• ${(Treatment}_i*{Time}_t)$= the interaction term between treatment and time, capturing the DID effect.

• $X_{it}$ represents the vector of covariates for individual i at time t.

• $y$ is the vector of coefficients for the covariates.

• ${\epsilon }_{it}$ is the error term.

Interpretation

The coefficient of primary interest is ${\beta }_3$, which represents the DID estimate of the intervention’s impact on HPV vaccine uptake. A positive and statistically significant ${\beta }_3$ would suggest that the integrated intervention led to an increase in vaccination rates in the intervention district compared with the comparison district.

Considerations for DID

• Robustness checks: The analysis will include robustness checks to assess the sensitivity of the results to different model specifications and assumptions. This may involve using alternative estimation methods, such as propensity score matching or synthetic control methods, to address potential confounding factors.

• Subgroup analysis: If the data allow, subgroup analyses will be conducted to explore whether the intervention’s impact varies across different groups of adolescents, such as those from different socio-economic backgrounds or with varying levels of access to healthcare.

• Qualitative insights: The qualitative data collected in the study will be used to complement and enrich the quantitative findings, providing a deeper understanding of the mechanisms through which the integrated intervention influenced HPV vaccine uptake and other outcomes.

• KA surveys (research question 2.1): Repeated measures analysis of variance will be used to evaluate the impact of the integrated intervention on adolescents’ KA related to SRHR. Changes in KA scores between baseline and endline will be compared between the two districts to assess the impact of the intervention.

Qualitative data analysis

The interviews and FGDs will be conducted in either the local language or English, based on the preference of the participants. The sessions will be audio-recorded to facilitate accurate transcription and ensure quality control. Transcripts originally in the local language will be translated into English for further analysis. The translated transcripts will then undergo thematic analysis, employing NVivo software to manage and organise the data. The coded excerpts will be subsequently grouped into themes, reflecting the key patterns and insights emerging from the qualitative data. To enhance the richness and depth of the thematic analysis, direct quotes from the interview participants will be incorporated, ensuring anonymity to protect their privacy.

Mixed methods integration (joint analysis)

The quantitative and qualitative data will be integrated at the interpretation stage using a convergent parallel design and a triangulation protocol. This approach will use the qualitative findings to explain and provide context for the quantitative results. For example, if the DID analysis (quantitative) shows a statistically significant increase in vaccine uptake in the intervention district, the thematic analysis of FGDs with adolescents and providers (qualitative) will be used to explore the perceived drivers of this change. We will specifically analyse themes related to the convenience of the integrated platform, the impact of the CSE content or the influence of community outreach activities to provide a richer, contextualised explanation of the quantitative findings and explore the ‘how’ and ‘why’ behind the observed effects.

Monitoring plan

Purpose of the plan

The monitoring plan is designed to ensure the effective collection, management and analysis of data throughout the project. This plan aims to maintain high data quality, facilitate continuous learning and support the achievement of project objectives. In the journey of integrating HPV vaccination with adolescent health services in Lao PDR, the Monitoring Plan will help track progress, identify challenges and inform decision-making to improve health outcomes for adolescents.

Timely production of quality data

Ensuring timely data production is a multifaceted challenge that extends beyond merely implementing electronic data recording forms and dashboards. One significant lesson from Health Poverty Action’s (HPA) operational research projects in the past is the lack of clear direction on who should use which forms and when. This often leads to confusion among field staff, resulting in inconsistent data collection practices. Additionally, the design of the forms themselves can be problematic. Poorly designed forms that are not user-friendly can hinder efficient data entry, causing delays and errors.

Another critical challenge is the lack of user confidence in using these electronic forms. Many field staff may not be familiar with digital data collection tools, leading to hesitancy and mistakes. This issue is compounded by a general lack of motivation among users, who may not see the immediate benefits of timely and accurate data entry. Without proper incentives and engagement, the enthusiasm for maintaining high data quality can wane.

Moreover, the timeliness and completion of data are sometimes not well-tracked. Optimal levels of motivation and technical aptitude within the central Monitoring and Evaluation (M&E) team will be pivotal in mitigating such risk. Without a robust system to oversee the entire data management process, it becomes difficult to ensure that data is submitted on time and is complete. The central M&E team will be mobilised to provide the necessary technical skills to effectively use the interactive dashboard and other data management tools, further addressing the issue.

To address these challenges, the monitoring plan incorporates several solutions aimed at improving the overall data collection process:

• Clear guidance and training:

  • Form usage: A comprehensive guide will be developed to clearly outline who will use which forms, when and how. This guide will be distributed to all field staff and stakeholders.

  • Training: Regular, hands-on training sessions will be conducted to build user confidence in using electronic data recording forms. These sessions will cover form navigation, data entry and troubleshooting common issues.

• Form design:

  • User-friendly design: Field staff will be consulted to design user-friendly forms that are intuitive and easy to navigate. The forms will be pilot tested, and feedback will be incorporated to improve usability.

  • Standardisation: Forms will be standardised to ensure consistency and ease of use across different data collection points.

• Motivation and engagement:

  • Regular feedback: Feedback loops are to be established where field staff can share their experiences and challenges with the central M&E team. This will help in addressing issues promptly and keeping the team engaged.

• Tracking and monitoring:

  • Interactive dashboard: An interactive data dashboard will be developed to provide real-time insights into data completion and timeliness. This dashboard will be accessible to all relevant stakeholders with monitoring responsibilities, enabling timely decision-making.

  • Regular check-ins: Regular check-ins will be conducted between the central M&E team and field staff to review data submission status and address any delays or issues.

• Capacity building:

  • Hands-on technical training: Hands-on training will be provided by the thematic health advisor and HPA Asia regional team for the central M&E team to enhance their technical aptitude in overseeing the data management system. This will include training on data validation, analysis and dashboard management.

  • Support system: A support system will be established where field staff and M&E team members can seek technical assistance and guidance as needed.

Field data management and quality systems

HPA uses KOBO Toolbox to contribute to the Laotian national data management systems. Operational Research field staff will collect the HPV vaccine coverage and other relevant data from the primary health facilities and enter the data into KOBO Toolbox monthly. To ensure data accuracy, field staff will check primary data quality. Finally, M&E staff validate and store on KOBO server as well as analyse and support data information for report purposes.

To ensure the quality of data, HPA will pay attention to the following features of data and information:

• Validity and precision: by collecting the relevant information for the indicators, the HPA will clearly define the indicators, ensure that they are Specific, Measurable, Achievable, Relevant, Time-bound (SMART) indicators, define baseline and target and ensure the quality of the tools which are used for data collection.

• Reliability: To ensure the reliability of the data, all related M&E focal staff and field staff will be trained on using tools and data key-in and analysis.

• Integrity: HPA will create the linkage between different types of tools and different times of measurement if one indicator is measured several times.

• Procedure for validation: Data will be checked from different sources and verification means.

• Through regular training and multiple levels of checks, HPA ensures it maintains and improves its strong controls over collection, recording and reporting of high-quality data. The responsibility of each level in quality control is shown in table 2.

Table 2. Roles and responsibilities in DQA.

Service provider (primary healthcare staff, educators)	Conduct integrated intervention with the target group at school and health centres and record into the relevant forms.
District research facilitator	Collect the service record form and enter the data into digital form (KOBO) monthly. Primarily conduct DQA to ensure the quality of data.
Research officer and M&E team	Track the submission weekly to ensure the integrated service data is uploaded into the system on time. Track the progress of the programme according to the indicator to inform achievements and challenges.
Research manager	Monthly DQA by dashboard and random checks. Prepare the biannual project report and other reports (if any) and submit the report timely. Track the progress of the programme according to the indicator to inform achievements and challenges.

DQA, data quality assurance; M&E, monitoring and evaluation.

Patient and public involvement statement

Patients and the public were involved in this study protocol design primarily through community consultations and engagement activities during the initial conceptualisation phase, informing the relevance of the research questions and preferred service delivery methods for adolescents. Their priorities regarding accessible and comprehensive SRH services, particularly in addressing high adolescent pregnancy rates and SRH literacy, were considered when developing the enhanced integrated service package. Adolescents and caregivers will be key informants in exploring their perceptions of the intervention (SO-4). Plans to disseminate the results to study participants and relevant wider communities include sharing findings through community meetings, local workshops and culturally appropriate information, education and communication (IEC) materials such as fact sheets and infographics.

Ethical considerations and dissemination

Ethics review

Ethical approval for the study has been received from University of Health Sciences (UHS) Research Ethics Committee (REC) in Laos with identification number of 833/REC dated 4 September 2024. Informed consent will be obtained from all participants or their legal guardians before any data collection. Confidentiality and privacy will be maintained throughout the study by anonymising data and ensuring secure storage of information. The study will adhere to international ethical guidelines for research involving human subjects. Any potential risks or harms to participants will be minimised, and appropriate measures will be taken to ensure their well-being.

Informed consent

Informed consent for adolescent girls and boys participating in the integrated service implementation research in Lao PDR should consider their age, maturity and understanding of the research. It is important to ensure that the adolescents are adequately informed and empowered to make decisions about their participation. The information provided to adolescent girls should be tailored to their age and level of understanding. Parental or guardian consent is required for participation in research. Adolescents aged 10–13 years are required to provide their own assent process, indicating their willingness to participate in the research. (online supplemental materials S02 and S03: Informed consent forms) This process involves explaining the research to the adolescent in a way that they can understand and seeking their agreement to participate. In addition, the research team will ask permission from schoolteachers as well. It is important to clarify the legal and ethical requirements for consent in Lao PDR and to involve parents or guardians as appropriate.

Risks and benefits

There are no direct physical risks in participation in this study. However, participants may face social risks such as stigma or discrimination related to HPV vaccination, particularly in communities where there is a lack of awareness or misconceptions about the vaccine. The HPV vaccine has a well-established safety profile, with the most common side effects being local adverse events, primarily pain, redness and swelling at the injection site. Systemic reactions like headache and dizziness were also observed but were generally mild and self-limiting. Serious adverse events were rare, and no association was found between HPV vaccination and new-onset chronic diseases or infertility.¹⁴

There are no direct monetary benefits in participating in this study, except small non-monetary incentives such as refreshments, hygiene items and monetary compensation of no more than US$5 per participant for their time in attending the surveys and interviews. Other potential benefits for the community and health system include increased access to HPV vaccination, cost-effectiveness and health system strengthening. An indirect benefit for participants is an increase in KA regarding SRHR among adolescent boys and girls. This research provides valuable insights for policymakers, healthcare practitioners and researchers to optimise the integration of HPV vaccination services in Lao PDR and similar settings.

Confidentiality

Confidentiality is a critical aspect of participating in HPV vaccine integrated service implementation research in Lao PDR. Several measures will be in place to ensure confidentiality for participants. Data collected from participants will be anonymised to protect their identities, involving assigning unique identifiers to participants and using these identifiers in place of personal information. Any personal health information collected during the research will be stored securely, with access restricted to authorised personnel only.

Protocol amendments

Any significant changes to the study protocol will be communicated transparently to all relevant parties, including the ethics committee, funder and registries. Modifications to eligibility criteria, outcomes or analyses are considered significant. The investigators will be informed directly, and the REC in Laos will be notified to ensure the study remains ethically sound. Trial participants will be informed of any changes that might affect their participation or the study’s objectives. Updates will also be submitted to trial registries and journals to maintain accurate records and ensure transparency. The principal investigator (PI) is required to notify the Secretary of the REC in the event of any of the following:

• Significant changes to the project, including the reasons for the change and any ethical implications.

• Serious adverse effects on participants and the actions taken to address those effects.

• Unforeseen events or unexpected developments that require notification.

• Changes in research personnel, including the PI’s inability to continue in that role.

• The expiry of insurance coverage for the research project.

• Delays of more than 12 months in the commencement of the project.

• Termination or closure of the project.

Declaration of interests

We, the investigators, declare that no financial and other competing interests exist for us for the overall trial and each study site.

Dissemination plan

The dissemination plan serves as a strategic roadmap for sharing our research findings on HPV integration with relevant stakeholders within Lao PDR and beyond. This plan outlines our objectives and identifies our target audience and methods of dissemination. It also provides an overview of the techniques we will use to disseminate our findings, the timeline for these activities and how we plan to evaluate our efforts. As we are at the start of our research project, the methods and plan might still be adapted to better fit the context at different stages.

Objectives

• To increase awareness about the importance and benefits of HPV vaccination and adolescent health services. We aim to ensure that the local community understands the research findings and their implications, and to encourage their active participation in the implementation of the vaccination programme.

• To influence policy and practice by sharing our research findings with key stakeholders, including policymakers and health practitioners. We aim to provide evidence to support the integration of HPV vaccination with adolescent health services, demonstrating its potential to increase HPV vaccine coverage and contribute to adolescent health outcomes.

• To contribute to the international body of knowledge on HPV vaccination and adolescent health services. We aim to share our findings with the global research community and international health organisations, providing evidence that can be used to inform similar initiatives in other countries.

Target audiences

The key target audiences for this dissemination plan are:

• Local community members, including young adolescents, their parents and direct community members, as well as related community health workers, district and provincial staff to increase awareness about the importance and benefits of HPV vaccination and adolescent health services.

• National stakeholders, such as policymakers and health practitioners from the ministry of health and the ministry of education, influence policy and practice.

• Global research community and international health organisations, including Gavi and WHO to contribute to the international body of knowledge on HPV vaccination and adolescent health services.

Dissemination methods

• IEC/Behaviour Change Communication (BCC) materials: IEC and BCC materials will be used to share key messages and findings. These could include brochures, posters and leaflets that can easily be distributed and understood by the community.

• Training workshops: Throughout the programme delivery, we will deliver training workshops for health practitioners and community health workers on the integration of services co-delivered with HPV vaccination.

• Policy brief: A brief will be prepared to be shared with policymakers in Lao PDR. This will summarise our findings and provide recommendations for policy for advantages of HPV integration with other health services and/or through different delivery methods.

• Workshops: We will organise workshops for key stakeholders, including those from the relevant ministries and departments. This will provide an opportunity to share our research, discuss the findings and facilitate knowledge and learning exchange among key stakeholders.

• Academic publication: We will aim to publish our research findings in academic journals. This will ensure they reach the wider research community and contribute to the global body of knowledge on HPV vaccination integration with SRHR education.

• Narrative reports: We will prepare narrative reports that detail our research process, findings and implications. These can be shared with a wide range of stakeholders.

• International conferences: We will present our findings at international conferences (and Gavi Global meetings). This will provide an opportunity to share our research with a global audience, receive feedback and network with other researchers in the field.

Overall study timeline

The project workplan was finalised by HPA, with the collaboration and agreement with implementation partners, UHS and NIP through the series of consultation meetings. The work plan was aligned with research project management series, ensuring (1) the feasibility under the local context and conditions of the country, (2) relevance to influencing factors such as school calendars and community local calendars, (3) availability of resources including budget and (4) willingness to actively participate by potential audiences. A simplified outline of research timeline can be seen in figure 3.

Figure 3. Timeline and contents (visual representation of the study timeline comparing the intervention district activities—including CSE, vaccination campaigns and training—vs the comparison district activities). CSE, comprehensive sexuality education; HE, health education.

Role of study funders

Gavi, the Vaccine Alliance, as the funder of this study, provides an overarching aim for the learning agenda. Gavi commissions a set of implementation research projects to contribute evidence on feasible, effective, integrated service approaches for adolescents to increase and sustain HPV vaccination access, equity and coverage in priority countries, and to test how integrated approaches could increase HPV coverage equitably and sustainably, as well as contribute to additional, applicable adolescent health outcomes.

The conceptualisation of the study in Lao PDR, the design of its study methodology, intervention, study procedures and analysis are primarily decided by the authors. Gavi provides comments on the study protocol, methodology and intervention design, with the authors retaining the final decision to submit the protocol and findings for publication under of the study, Gavi, provides an overarching aim of the learning agenda. Gavi, the Vaccine Alliance, commissions a set of implementation research projects to contribute evidence on feasible, effective, integrated service approaches for adolescents to increase and sustain HPV vaccination access, equity and coverage in priority countries. to test how integrated approaches could increase HPV coverage equitably and sustainably, as well as contribute to additional, applicable adolescent health outcomes.

The conceptualisation of the study in Laos PDR, design of its study methodology, intervention, study procedures and analysis are decided by the authors. Gavi makes comments on the study protocol, methodology and intervention design. Authors make the decision to submit the protocol and findings for publication.