Safety and immunogenicity of a vaccine against coxsackieviruses B (PRV-101) - follow-up of the first-in-human phase 1 trial

BackgroundCoxsackie B viruses cause acute infections and have been linked to chronic diseases like cardiomyopathies, type 1 diabetes, and celiac disease. Despite their clinical significance, no vaccines exist for coxsackie B virus types. PRV-101, a new candidate vaccine covering five coxsackie B virus types, showed good immunogenicity and tolerability in a phase 1 trial (PROVENT). MethodsWe conducted an extended follow-up of the PROVENT trial to assess the long-term immune response and safety of PRV-101. A total of 26 participants from the original cohort (n=32) were enrolled for additional testing approximately two years post-immunization (11 high-dose, 10 low-dose, and 5 placebo). Coxsackie B virus -specific antibody responses were measured and compared to earlier time points. ResultsPRV-101 was safe with no late adverse effects or emergence of autoantibodies linked to type 1 diabetes or celiac disease. Neutralizing virus antibodies remained elevated, with a clear dose-dependent response. In the high-dose group, antibodies against all coxsackie B virus types reached presumably protective levels, except for coxsackie B virus 2, where two participants turned seronegative. ELISA tests confirmed elevated antibody levels against coxsackie B virus proteins. DiscussionThese results suggest that PRV-101 induces durable antibody responses lasting at least two years. The findings support the continued development of PRV-101 for preventing both acute coxsackie B virus infections and chronic diseases like type 1 diabetes and celiac disease.