Related Experiment Video
Updated: Sep 9, 2025
Protocol for Recombinant RBD-based SARS Vaccines: Protein Preparation, Animal Vaccination and Neutralization Detection
Published on: May 2, 2011
Homologous and Heterologous Vaccination Regimens with mRNA and rVSV Platforms Induce Potent Immune Responses Against
Tomaz B Manzoni1, Jonna B Westover2, Kendall A Lundgreen1
1Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Background:
Severe fever with thrombocytopenia syndrome virus (SFTSV) is a highly pathogenic bunyavirus with a high case-fatality ratio for which there is no approved vaccine. Studies have assessed different vaccine technologies. However, few studies have yet assessed the immunogenicity of heterologous prime-boost regimens.
Methods:
Here, we compare a lipid nanoparticle (LNP)-encapsulated nucleoside-modified mRNA-based vaccine encoding the SFTSV glycoproteins, Gn and Gc, to our recently described recombinant VSV SFTSV (rVSV-SFTSV) vaccine in single dose, homologous, and heterologous prime-boost regimens in mice.
Results:
We show that all regimens protect from pathogenic SFTSV challenge and elicit strong long-lasting antibody responses. Furthermore, strong cellular immunity is elicited by mRNA-LNP immunizations and by heterologous immunization with an rVSV-SFTSV prime and mRNA-LNP boost. Cellular responses robustly polarized towards a type 1 response, characterized by high levels of IFNγ, TNFα, and IL-2. Immunization with mRNA led to a mixed type 1/type 2 immune response, as determined by antibody isotypes IgG1 and IgG2c. We found that homologous immunization leads to stronger antibody responses while heterologous immunization drives a slightly stronger cellular response.
Conclusions:
Taken together, the vaccine platforms described here represent strong vaccine candidates for further development.
