Adherence to vaccination schedules in patients under active oncological treatment and follow-up: protocol for a systematic review and meta-analysis

Abstract

Abstract Introduction Vaccination is a key public health strategy for preventing infectious diseases and is particularly relevant for patients with cancer because of disease-related and treatment-related immunosuppression. Optimising vaccination status should be considered a fundamental component of care for this population; however, in clinical practice, vaccination may be neglected during active treatment and survivorship follow-up. Methods and analysis This systematic review and meta-analysis protocol will include observational studies (cross-sectional, case-control and cohort studies) evaluating adherence to age-based and seasonality-based vaccination schedules among adults with cancer who are undergoing active oncological treatment or post-treatment follow-up. Eligible vaccines include COVID-19, influenza, invasive pneumococcal disease, tetanus/diphtheria/pertussis, herpes zoster, human papillomavirus and hepatitis B vaccines. Searches will be conducted in PubMed/MEDLINE, Embase, Web of Science, Scopus, Cochrane Library, ScienceDirect, CINAHL and LILACS without restrictions on language or publication date. Study selection and data extraction will be performed independently by two reviewers, with disagreements resolved by discussion or by a third reviewer. Risk of bias will be assessed using the Joanna Briggs Institute tool for cross-sectional studies and the Newcastle-Ottawa Scale for cohort and case-control studies. The certainty of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. When appropriate, random-effects meta-analysis will be performed using RevMan V.5.2.3; otherwise, findings will be synthesised narratively. The protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) reporting guidance. Article selection and data collection will be carried out from October 2026 to January 2027. Ethics and dissemination Ethical review is not required because this study will use only publicly available published literature. The findings will be disseminated through publication in a peer-reviewed journal and scientific presentations. Prospero registration number CRD420261295899.