The development of effective vaccines targeting human papillomavirus (HPV) has significantly contributed to disease prevention, highly relevant in immunosuppressed patients who have higher incidence of HPV-related cancers than their non-immunosuppressed counterparts. However, the acceptance and uptake of the HPV vaccine among immunosuppressed individuals pose unique challenges. Immunocompromised patients’ acceptance of the HPV vaccine is influenced by multifaceted factors, including concerns about safety and effectiveness, interactions with immunosuppressive medications and uncertainties due to their compromised immunity. This systematic review aims to identify the main factors influencing HPV vaccine acceptance among immunosuppressed patients.

A comprehensive search strategy will be executed across databases such as MEDLINE/PubMed, Embase, Scopus, Web of Science, ScienceDirect, Latin American and Caribbean Literature in Health Sciences, Cumulative Index to Nursing and Allied Health Literature and Cochrane Database. The review will encompass the three WHO-endorsed HPV vaccines (quadrivalent, bivalent and nonavalent) and will consider studies related to HPV vaccines and their administration. The scope includes study focusing on immunosuppressed patients who received organ transplants, cancer treatments or are HIV-positive. No temporal restrictions will be applied, and searches will be conducted until December 2025. Observational studies, including retrospective/prospective cohorts, case–control and cross-sectional studies, reporting factors influencing HPV vaccination in immunosuppressed populations will be included. Studies with overlapping patient populations will be excluded. Data extraction will include study details, demographics, vaccine type, risk/protective factors, outcomes and medical history. Validation and cross-verification will ensure data accuracy. Risk of bias will be assessed using ROBINS-I (Risk Of Bias In Non-randomised Studies of Interventions), and GRADE (Grading of Recommendations Assessment, Development and Evaluation) will rate evidence certainty. Meta-analysis, guided by Cochrane and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, will employ fixed/random-effects models, assessing heterogeneity using I² statistics.

This research will analyse previously published data, so ethical approval is not required. The results of the systematic review will be submitted for publication in a peer-reviewed journal.

CRD42023452537.

Adolescence and youth are periods of significant maturational changes, which seem to involve greater susceptibility to disruptive events in the brain, such as binge drinking (BD). This pattern—characterised by repeated episodes of alcohol intoxication—is of particular concern, as it has been associated with significant alterations in the developing brain. Recent evidence indicates that alcohol may also induce changes in gut microbiota composition and that such disturbances can lead to impairments in both brain function and behaviour. Moreover, there is evidence suggesting that microbiota-targeted interventions (psychobiotics) may help mitigate alcohol-induced damage in individuals with chronic alcohol use, positively influencing cognitive and brain functioning. However, the triadic relationship between BD, gut microbiota and brain structure/function, as well as the therapeutic potential of gut microbiota-targeted interventions in young binge drinkers, remains largely unexplored.

This double-blind, parallel, randomised controlled study aims to evaluate whether a BD pattern disrupts gut microbiota diversity in young college students (primary outcome). Additionally, it seeks to determine whether alcohol-induced alterations in the microbial composition and function are associated with immunological, cognitive, neurostructural and neurofunctional impairments (secondary outcomes). A total of 82 college students (36 non/low drinkers and 46 binge drinkers (BDs)), matched for age and sex, will be recruited from the University of Minho (Portugal). During the pre-intervention phase, all participants will undergo a comprehensive assessment protocol, including gut microbiota profiling, measurement of inflammatory markers, neuropsychological testing and structural and functional MRI. BDs will then be randomly assigned to a 6-week intervention with either a prebiotic (inulin) or a placebo (maltodextrin). Post-intervention assessment will mirror the baseline protocol, and craving and alcohol use will be monitored for 3 months.

The present protocol was approved by the Ethics Committee for Social and Human Sciences of the University of Minho (CEICSH 078/2022), ensuring compliance with national and international ethical guidelines, including the Declaration of Helsinki. Participation is voluntary and preceded by informed consent, with confidentiality and data processing safeguarded in accordance with the General Data Protection Regulation. All procedures are safe and non-invasive, and the prebiotics used are recognised as food ingredients in Europe, hold Generally Recognized as Safe status in the USA and are classified as dietary fibres by the Food and Drug Administration. Findings will be disseminated in national and international scientific forums, with preference for publication in open-access, peer-reviewed journals.

NCT05946083