The proposed project aims to continue research for development of a vaccine protective against the pathogenic equine parasite Strongylus vulgaris. The ongoing work to establish appropriate in vitro models to screen the effect of candidate vaccine antigens/adjuvants will be continued. Cytokine screenings in cultures of equine PBMC and intestinal organoids will enable studies of both the systemic (PBMC) and local (organoids) response to parasite antigens. Our main antigen candidate, the recombinant protein SvSXP, will be evaluated together with a novel adjuvant, G3, first in our in vitro systems and thereafter in an immunisation trial in collaboration with experts on parasite immunology at the University of Kentucky. In search of additional vaccine antigens a bacteriophage cDNA library constructed from migrating S. vulgaris larvae will be utilized. Bacteriophage clones expressing promising larval antigens will be further propagated and tested for inclusion in the vaccine formula.