Paediatric Solid Tumour Vaccines: Current Processes, Prevailing Challenges and Future Perspectives

Over the past several decades, cure rates for paediatric hematologic malignancies have improved due to advances in cancer therapy. However, numerous obstacles limit the therapeutic efficacy of paediatric solid tumours, including the tumour's immunosuppressive microenvironment and the lack of specific tumour antigens for targeted therapy. Cancer vaccines, a form of immunotherapy, have been under development for more than half a century. Advances in immunology, materials science, sequencing technologies and bioinformatics have revolutionised cancer vaccine development, achieving substantial success in the prevention and treatment of solid tumours. Despite these achievements, the application of cancer vaccines developed for adults is not fully transferable to paediatric solid tumours because of differences in immune status and metabolic capacity. In clinical practice, most solid tumour vaccines designed for adults are applied directly to paediatric patients without modifications tailored to the unique features of the paediatric immune system. Limited attention has been given to designing cancer vaccines with improved efficacy and reduced toxicity for children and infants. This review discusses paediatric solid tumour vaccines from the immune system against tumour to different antigen types of cancer vaccines, illustrating the unique cancer-immunity cycle of young people and some potential strategies for vaccine modification. Additionally, it discusses the application of paediatric solid tumour vaccines through clinical trial data for conditions such as neuroblastoma, brain tumours and sarcomas. Challenges and potential solutions for enhancing vaccine efficacy, minimising side effects and broadening clinical applications are also addressed.