What Do Adolescents Think about Vaccines? Systematic Review of Qualitative Studies

"Although adolescents are central to vaccination programs, their views around vaccines are frequently underrepresented in qualitative literature...and warrant a dedicated systematic review."

Adolescence presents a key opportunity to build vaccine-related health literacy and promote vaccine confidence and uptake. The importance of understanding and addressing adolescents' vaccine information needs and including them in vaccine decision-making is increasingly affirmed. However, their views around vaccines are frequently underrepresented in qualitative literature. This systematic review of qualitative studies is designed to identify and summarise existing evidence on adolescents' own understanding of vaccines and experiences with vaccine decision-making, including self-consent when applicable.

On July 8 2021 and then May 28 2022, the researchers searched CINAHL, Embase, Ovid Medline, and Psych Info databases for studies that provided primary qualitative data from adolescents (aged 10-19) published as full-text in a peer-reviewed journal or as a graduate thesis. Only English language studies were considered. There were no restrictions on publication date. Out of 3,559 individual records, 59 studies were included. The majority of the studies were conducted in high-income countries, and 75% focused on human papillomavirus (HPV) vaccines, with the remaining studies looking at COVID-19, meningococcal, hepatitis B, and influenza vaccines - or adolescent experiences with vaccines in general. Adolescent self-consent was explored in 7 studies. Perspectives from sexual and gender minorities were lacking across studies.

Select findings:

• Studies included in the review demonstrate adolescents have some understanding of vaccines and vaccine-preventable diseases but are oftentimes unsure why a specific vaccine is recommended for them and may have questions and concerns about vaccine safety and effectiveness. Specific fears around long-term side effects of vaccines were highlighted in HPV studies; sources of (mis)information appeared to have originated primarily from parents or other caretakers and less commonly peers or the media.
• Because parents were usually required to provide consent for and sometimes pay for the vaccine, adolescents in many studies explicitly or implicitly assumed parents had or were responsible for obtaining and evaluating vaccine information. A notable exception to this tendency: marginalised adolescents who could not rely on parents for health-related advice. Also, some adolescents were uncomfortable discussing HPV vaccine with their parents because it would involve talking about sexuality and wished for adolescent-friendly information.
• Adolescents wished for more detailed vaccine information to be provided in school settings by healthcare professionals at the school and occasionally by teachers. They may perceive existing vaccine-related information provided in schools or via community healthcare providers as being directed towards their parents/caretakers and may not be motivated to seek out vaccine information for themselves or to actively participate in vaccine decision making.
• While adolescents described obtaining vaccine information from traditional and online media, face-to-face interactions and opinions from trusted adults remained important. Peers were not commonly described as a source of vaccine information. Some adolescents said peers could be sources of rumours and fearmongering about vaccines, especially for vaccination pain.
• Several studies highlighted how adolescents were influenced by the current events popularised in the media. Among Colombian adolescents, HPV vaccine perceptions were negatively affected by local media reports featuring a young women who allegedly experienced debilitating side effects from the vaccine.
• Seven of the included studies specified that participating adolescents had the legal ability to consent to or decline vaccines under their local jurisdiction framework and examined whether self-consent was actually exercised as part of the vaccination programme. Even if self-consent was available legally, the option to self-consent was not consistently offered to adolescents in real life.
• Several studies explored adolescent involvement in the vaccine decision-making process when the final decision and consent were parental. While some adolescents perceived being involved in vaccine discussions as a step towards autonomy, others felt they were given a "false choice" in which the only legitimate option was to agree or simply deferred to parents to make the decision for them.

Selective recommendations emerging from these findings include:

• Identify pertinent vaccine information and appropriate communication methods to actively engage adolescents to increase vaccine-related literacy and acceptability of vaccines among them.
• Acknowledge legal and socio-cultural contexts in which adolescent vaccination programmes are taking place - e.g., legislative tensions that can occur when young people wish to be vaccinated against parental wishes.
• Leverage the potential schools have to play in providing adolescent-focused vaccine education (beyond the information provided in vaccine information sheets), which students can share at home - potentially improving knowledge among their parents.
• Recognise that discussing vaccines with trusted healthcare provider (and receiving their unequivocal recommendation) may influence vaccine confidence and uptake among adolescents.
• Empower adolescents to learn and make informed decisions about vaccines by explaining how to look for credible sources of digital health information.

In terms of avenues for future research, the authors suggest that qualitative literature about adolescent vaccines would be enriched by studies that: examine vaccines other than the HPV vaccine, investigate adolescent vaccine programmes in low- and middle-income countries (LMICs), include a more nuanced inquiry into how adolescents access and interpret vaccine information available through digital and traditional media, and deliberately elicit vaccine experiences of adolescents with diverse sexual orientation and gender identities.

In conclusion, the findings of this systematic review may help to inform adolescent vaccination programmes, to support efforts to promote vaccine-related health literacy among adolescents, to facilitate informed decision-making, and to guide further research.