The effect of Toll-like receptor agonists on the immunogenicity of MVA-SARS-2-S vaccine after intranasal administration in mice
A respiratory vaccination has the potential to offer immediate protection against novel respiratory pathogens. Previously, we showed that respiratory delivery of Modified Vaccinia Virus Ankara-based COVID-19 vaccine candidate, MVA-SARS-2-S, induces protective immune responses against the SARS-CoV-2 in rodents. In our new study, recently published in Frontiers in Cellular and Infection Microbiology (Frontiers | The effect of Toll-like receptor agonists on the immunogenicity of MVA-SARS-2-S vaccine after intranasal administration in mice (frontiersin.org)), we examined how adjuvant effects of Toll-like receptor (TLR) agonists affect modulate mucosal immune responses induced by a single dose of intranasally applied MVA-SARS-2-S. "Importantly, our data indicate that the TLR3 agonist, poly(I:C), boosted cellular responses to the respiratory-delivered MVA-SARS-2-S." points out Ms. Kim Do, the first author of this study. "On the other hand, the TLR4 agonist, LPS, and TLR9 agonist, CpG ODN, did not boost MVA-SARS-2-S-specific immunity despite affecting various parts of vaccine-induced immune responses." Together, our results indicate that further optimization of adjuvants targeting TLRs could pave the way for potent single-dose MVA-based vaccine formulations against respiratory pathogens.