Lyophilized mRNA-lipid nanoparticle vaccines with long-term stability and high antigenicity against SARS-CoV-2

Abstract

Advanced mRNA vaccines play vital roles against SARS-CoV-2. However, due to the poor stability, most current mRNA delivery platforms need to be stored at -20 °C or -70 °C. Here we present lyophilized thermostable mRNA loaded lipid nanoparticles, which could be stored at room temperature with long-term stability. We demonstrate the applicability of lyophilization techniques to different mRNA sequences and lipid components. Three lyophilized vaccines targeting wild-type, Delta and Omicron SARS-CoV-2 variant were prepared and demonstrated to be able induce high-level of IgG titer and neutralization response. In the Delta challenge in vivo experiment, the lyophilized mRNA vaccine successfully protected the mice from infection and clear the virus. This lyophilization platform could significantly improve the accessibility of mRNA vaccine or therapeutics, particularly in remote regions.

Self-Amplifying RNA Vaccine Candidates: Alternative Platforms for mRNA Vaccine Development

“…Incorrect storage can lead to oxidation and hydrolysis of the RNA and may alter their function [ 65 ]. Lyophilization might be an alternative storage method as it may enable long-term stability at higher temperatures [ 66 , 67 ].…”

mRNA-based modalities for infectious disease management

“…During lyophilization, the removal of water takes place via sublimation at low temperature under vacuum. Generally, lyophilization is comparatively a mild drying method and believed to enhance the stability issues mostly related to colloidal nanoparticles (NPs) and/or macro-biomolecules [145,146].…”

Advancing mRNA technologies for therapies and vaccines: An African context

“…Ai et al. recently studied the physical LNP characteristics, encapsulation efficiency, and size of lyophilized mRNA-LNPs at different temperatures and time points, albeit only for 18 days ( 193 ). Lyophilized mRNA-LNPs stored at 4°C and 25°C were stable for at least 18 days, showing no changes in size, encapsulation, and RNA integrity, while those stored at 40°C displayed an increase in size, without loss of RNA integrity or encapsulation efficiency.…”

“…In vivo results showed comparable luciferase expression and anti-SARS-CoV-2 IgG titers when compared to fresh mRNA-LNPs. In addition neutralization antibodies against different SARS-CoV-2 variants were established and transgenic mice were protected in an infection-based model ( 193 ). An in-depth investigation into lyophilization of mRNA-LNPs recently revealed that storage at 4°C and below allowed maintenance of LNP size, polydispersity index and encapsulation efficiency for 24 weeks ( 182 ).…”