Current Efficacy of Multiepitope Vaccines Against Helminths: A Systematic Review.

Background: Vaccination represents an efficient way to control communicable diseases. Reliable vaccines would reduce the use of anthelmintics drugs and fight against the concern of anthelmintics resistances. Unfortunately, anthelmintic vaccines face many difficulties in their development. One of the most innovative vaccine models in this field is multiepitope vaccines since, based on advances in immunoinformatics, they facilitate immunization against parasites at different stages of their cycles. Objective: In this study, we evaluate the published efficacy of multiepitope vaccines against helminths. Methods: Independent reviewers conducted a comprehensive search of multiple databases until September 20th 2024, following PRISMA 2020 guidelines. The review included original in vivo protection studies using chimeric vaccines with antigenic epitopes in experimental models. Key information was summarized, tabulated, and analyzed, and risk of bias was assessed using the SYRCLE risk tool. Results: A total of 15 preclinical studies were included. In those immunization experiments, parasite load reductions varied from 12.4% to 100%. Conclusions: Overall, this study shows protections in parasite load or lesion in 50-80% and significant survival rates using experimental vaccines including B- and T-cell epitopes in a wide range of helminthic infections. Given the variability of the experiments and the limited available data, there was not a clear correlation between protections and immune responses. Confirmation trials are needed to corroborate the protection and immunological mechanisms reached not only in this initial valuable study but also with other multiepitope candidates.