Efficacy of the Vaccine Candidate Based on the P0 Peptide against Dermacentor nitens and Ixodes ricinus Ticks

Funding Information: This research was funded by the Center for Genetic Engineering and Biotechnology, Havana, Cuba, the Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Portugal, and the Czech Science Foundation grant no. 20-05736S. Mobility was supported by the CYTED Network INCOGARR 110RT0541. Funding Information: The authors thank DVM Alejandro Peguero for his valuable medical attention to horses during the experiment in the San Cristóbal Company in Cuba and all personnel of this company in charge of caring for the animals. Fundação para a Ciência e a Tecnologia (GHTM-UID/04413/2020 and LA-REAL—LA/P/0117/2020). FCT project—TickGenoMi PTDC/SAU-PAR/28947/2017. Publisher Copyright: © 2023 by the authors.The control of ticks through vaccination offers a sustainable alternative to the use of chemicals that cause contamination and the selection of resistant tick strains. However, only a limited number of anti-tick vaccines have reached commercial realization. In this sense, an antigen effective against different tick species is a desirable target for developing such vaccines. A peptide derived from the tick P0 protein (pP0) conjugated to a carrier protein has been demonstrated to be effective against the Rhipicephalus microplus, Rhipicephalus sanguineus, and Amblyomma mixtum tick species. The aim of this work was to assess the efficacy of this peptide when conjugated to the Bm86 protein against Dermacentor nitens and Ixodes ricinus ticks. An RNAi experiment using P0 dsRNA from I. ricinus showed a dramatic reduction in the feeding of injected female ticks on guinea pigs. In the follow-up vaccination experiments, rabbits were immunized with the pP0-Bm86 conjugate and challenged simultaneously with larvae, nymphs, and the adults of I. ricinus ticks. In the same way, horses were immunized with the pP0-Bm86 conjugate and challenged with D. nitens larva. The pP0-Bm86 conjugate showed efficacies of 63% and 55% against I. ricinus and D. nitens ticks, respectively. These results, combined with previous reports of efficacy for this conjugate, show the promising potential for its development as a broad-spectrum anti-tick vaccine.publishersversionpublishe

Hotspot of Crimean-Congo Hemorrhagic Fever Virus Seropositivity in Wildlife, Northeastern Spain

We conducted a serosurvey for Crimean-Congo hemorrhagic fever virus antibodies in various wildlife species in Catalonia, northeastern Spain. We detected high seroprevalence in southern Catalonia, close to the Ebro Delta wetland, a key stopover for birds migrating from Africa. Our findings could indicate that competent virus vectors are present in the region.info:eu-repo/semantics/publishedVersio