LmCen−/− based vaccine is protective against canine visceral leishmaniasis following three natural exposures in Tunisia
Year: 2025
Type: article
Abstract: Dogs are the main reservoir host of Leishmania infantum, etiological agent of zoonotic visceral leishmaniasis (ZVL). An effective vaccine against Canine Visceral Leishmaniasis (CVL) will help the control and elimination of ZVL. In this study, we evaluated in dogs the safety, immunogenicity, and efficacy of a live attenuated Leishmania major Centrin gene-deleted (LmCen−/−) as a vaccine. Two doses (106 or 107) of LmCen−/− vaccine were administered intradermally in a prime-boost regimen. Both vaccine doses induced equally high level of IgG anti-Leishmania and exhibited strong antigen-specific cellular responses with IFN-γ production by CD4 + T cells one-month post-immunization. A second cohort of dogs was vaccinated with 106 LmCen−/− parasites one month prior to their transfer to a CVL endemic focus in Northern Tunisia for exposure to sand fly bites during three successive transmission seasons. Dogs were exposed to bite from naturally infected sandflies for 3–5 months per year. Our results showed that only 1/11 vaccinated dogs became PCR positive for Leishmania and developed clinical signs of CVL. In contrast, 4/11 unvaccinated dogs were tested PCR positive for Leishmania and displayed oligosymptomatic CVL, demonstrating that immunization with LmCen−/− vaccine confers long-term protection with an efficacy of 82.5% against CVL in natural transmission settings.
Source: npj Vaccines
Authors: Thouraya Boussoffara, Imen Labidi, Malek Trimèche, Ifhem Chelbi, Khalil Dachraoui, Nourhane Msallem, Mohammed Abdo Saghir Abbas, Saifedine Cherni, Kamaleshwar P. Singh, Swarnendu Kaviraj, Ranadhir Dey, Sanjay Varikuti, Sreenivas Gannavaram, Lais da S. Pereira, Wen-Wei Zhang, Patrick Lypaczewski, Shinjiro Hamano, Hirotomo Kato, Sanjay Singh, Hechmi Louzir, Hira L. Nakhasi, Abhay R. Satoskar, Greg Matlashewski, Elyes Zhioua
Institutions: Tunis University, Institut Pasteur de Tunis, Tunis El Manar University, Center for Biologics Evaluation and Research, United States Food and Drug Administration, The Ohio State University, McGill University, Nagasaki University, Institute of Tropical Medicine, Nagasaki University, Jichi Medical University
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,890
Awards: A live attenuated vaccine for leishmaniasis, Establishment of on-site rapid diagnosis and risk analysis of cutaneous leishmaniasis, Understanding the molecular basis of pathogen transmission by arthropod vectors, Understanding the function of the peritrophic matrix in blood-sucking insects: Toward a novel strategy to inhibit pathogen development by enhancing its barrier function
OpenAlex ID: W4407574409