High protective efficacy of a recombinant Fer2 vaccine against Dermacentor marginatus infestations

Dermacentor marginatus is an important disease vector in China, yet current control methods remain heavily reliant on chemical acaricides. This study evaluated the vaccine potential of Ferritin 2 from D. marginatus (DmFer2). The DmFer2 gene was cloned, expressed as a recombinant DmFer2 (rDmFer2) in a prokaryotic expression system, and subsequently used to immunize rabbits. Immunization elicited high anti-rDmFer2 antibody titers, which peaked at a detectable maximum of 1:25,600 on day 35, and significantly reduced tick fecundity and altered tick feeding kinetics in challenge trials. Specifically, rDmFer2 vaccination resulted in prolonged engorgement cycle (8.25% relative extension), and reductions in the oviposition rate (19.64%), egg mass weight (43.74%), and hatching rate (38.5%), leading to an overall anti-tick efficacy of 82.1%. These results demonstrate, for the first time, that rDmFer2 is a highly effective vaccine candidate against D. marginatus. Its protective effects are primarily attributed to disrupting tick iron metabolism and interfering with tick feeding dynamics, and provide a theoretical and experimental foundation for the development of sustainable tick control strategies.