Exploring the Barriers and Facilitators to Vaccination among the Immunocompromised Population: A Scoping Review

Objective Individuals with immune deficiency are at increased risk of morbidity and mortality caused by vaccine-preventable diseases. Despite the advantages of vaccination, some members of this high-risk population question or refuse vaccines. This study aimed to identify the barriers and facilitators to vaccination among people with altered immunocompetence via a scoping review. Methods This review was guided by the Joanna Briggs Institute's framework to identify relevant publications examining factors influencing vaccine behaviours in immunocompromised populations. Our search encompassed studies published from January 1974 to July 25, 2022, across various databases, including MEDLINE (Ovid), CINAHL, PsycINFO, Web of Science, Cochrane Database of Systematic Reviews, EMBASE, ProQuest, TRIP, CHODARR, OpenGrey, and Google Scholar. Both peer-reviewed and grey literature were incorporated, irrespective of language, in line with predefined criteria. The synthesis specifically addressed vaccine uptake and hesitancy outcomes, along with factors acting as barriers or facilitators. Results Seventy-six publications were included, addressing both congenital and acquired immunodeficiencies. Notably, vaccines for COVID-19, Influenza, Pneumococcal disease, and Hepatitis B featured prominently. Vaccine uptake rates exhibited a wide range, spanning from 5.6–96.7%. Factors deterring vaccination uptake included concerns about adverse vaccine effects, doubts about vaccine benefits, lack of healthcare professional recommendations, and younger age. Conversely, predictors of higher vaccination uptake comprised older age, perceived vulnerability to vaccine-preventable diseases, higher education attainment, prior vaccination history, and longer immunosuppression duration. Conclusions Our study highlights that immunocompromised individuals' vaccination behaviours are influenced by unique health-related factors, such as concerns about vaccine safety and reliance on physicians due to limited vaccine knowledge. These insights are pivotal in the formulation of effective public health policies and interventions that address safety concerns and knowledge gaps and enhance understanding to support informed vaccination decisions.