The COVID-19 pandemic highlights the opportunity for mRNA vaccines and their nanotechnology carriers to make an impact as a countermeasure to infectious disease. As alternative to the synthetic lipid nanoparticles or mammalian viruses, we developed a tobacco mosaic virus (TMV)-based mRNA vaccine delivery platform. Specifically, purified coat protein from TMV was used to package a self-amplifying Nodamura replicon expressing the receptor binding domain (RBD) from the Omicron strain of SARS-CoV-2. The replicon construct contains the origin of assembly sequence from the tobacco mosaic virus (TMV) for encapsulation and mRNA stabilization. The nanoparticle vaccine was obtained through in vitro assembly using purified TMV coat proteins and in vitro transcribed mRNA cassettes. Cell assays confirmed delivery of self-amplifying mRNA vaccine, amplification of the transgene and expression of the target protein, RBD, in mammalian cells. Immunization of mice yielded RBDspecific IgG antibodies that demonstrated neutralization of SARS-CoV-2 using an in vitro neutralization assay. The TMV platform nanotechnology does not require ultralow freezers for storage or distribution; and the in vitro assembly method provide ‘plug-and-play’ to adapt the vaccine formulation rapidly as new strains or diseases emerge. Finally, opportunity exists to produce and self-assemble the vaccine candidate in plants through molecular farming techniques, which may allow production in the region-for the region and could make a contribution to less resourced areas of the world.
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The influenza universe in an mRNA vaccine
The greatest challenge to preventing the next influenza pandemic is the extensive diversity within the influenza virus family ( 1 ). At present, 20 lineages of influenza A and B viruses have been identified, each containing numerous strains ( 2 , 3 ). Current influenza vaccines, composed of four influenza viral antigens, provide little protection beyond the viral strains targeted by the vaccines. Universal influenza vaccines that can protect against all 20 lineages could help to prevent the next pandemic ( 4 ). Designing and manufacturing a vaccine that can provide such broad protection has been challenging, but the demonstration of the feasibility of mRNA–lipid nanoparticle COVID-19 vaccines offers a possible strategy ( 5 ). On page 899 of this issue, Arevalo et al. ( 6 ) report an influenza vaccine, using mRNA–lipid nanoparticle technology incorporating representatives of all 20 influenza virus lineages, that protected mice and ferrets from diverse influenza viruses. This provides a pathway to a universal influenza vaccine.
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- Award ID(s):
- 1933525
- PAR ID:
- 10406380
- Date Published:
- Journal Name:
- Science
- Volume:
- 378
- Issue:
- 6622
- ISSN:
- 0036-8075
- Page Range / eLocation ID:
- 827 to 828
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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