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Single shot protection against Lassa virus in animals

By 4th October 2019 October 8th, 2019 No Comments

Researchers in Paris, Lyon and Strasbourg have created a vaccine for Lassa fever that completely shields macaques from infection with only a single dose – an important advantage when designing vaccines intended for vaccination campaigns in the field. Their findings – based on a comparison of three promising vaccine candidates – indicate that the vaccine could help protect populations in remote areas from both routine transmission and larger outbreaks of Lassa virus (LASV).

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The MOPEVAC-LAS and MeV-NP-EXO vaccines – two vaccine candidates tested by the scientists – inserted Lassa glycoprotein (green) into hamster ovary cells. Credit: M. Mateo et al.,Science Translational Medicine (2019)

LASV is a dangerous emerging pathogen that causes thousands of deaths each year in Western Africa. The disease has been classified as an epidemic threat by the World Health Organization (WHO), but an effective vaccine has been held back by issues with safety as well as by the high genetic diversity of the virus. In this new study, the researchers, led by Sylvain Baize, tested three promising vaccine platforms for LASV: two that make use the measles virus (MeV) and one that uses the Mopeia virus (MOPV) as a delivery mechanism. They first administered the vaccines to macaques and compared protein signatures and immune cell responses in the animals after a single dose. The first two candidates, MeV-Z and MOPEVACLAS, both provided at least some protection to a lethal LASV challenge and were well-tolerated, but the most effective candidate was an MeV vaccine based on the LASV nucleoprotein (NP). This vaccine provided robust immunity, as evidenced by a lack of LASV RNA after exposure, and all four vaccinated macaques displayed no clinical symptoms after LASV exposure.

The authors, reporting their work in Science Translational Medicinenote that the MeV-NP vaccine has been selected by the Coalition for Epidemic Preparedness Innovation for clinical development in the near future.

The researchers are from the Unité de Biologie des Infections Virales Emergentes, Institut Pasteur, Lyon, the Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, INSERM U1111, Ecole Normale Supérieure de Lyon, Université Lyon 1, CNRS UMR5308, Lyon, ViroScan3D SAS, Trévoux, the Bioinformatics and Biostatistics Hub–Department of Computational Biology, USR 3756 CNRS, Institut Pasteur, Paris, the Laboratoire P4 INSERM–Jean Mérieux, INSERM US003, Lyon, SILABE, Université de Strasbourg, Fort Foch, Niederhausbergen, the Laboratoire Innovations Technologiques pour la Détection et le Diagnostic (LI2D), Service de Pharmacologie et Immunoanalyse (SPI), Commissariat à l’Energie Atomique, Bagnols-sur-Cèze and Viral Genomics and Vaccination, Institut Pasteur, CNRS UMR-3569, Paris, France.

Read the research paper: Vaccines inducing immunity to Lassa virus glycoprotein and nucleoprotein protect macaques after a single shot. M. Mateo et al. Science Translational Medicine 10.1126/scitranslmed.aaw3163

Materials provided by the American Association for the Advancement of Science (AAAS).