VirologyJan 24, 2026

Combining mRNA vaccines for PRRS virus boosts immune defense and protection in piglets

mRNA Technology Weekly Brief ↗PubMed ↗DOI ↗

Updated Jan 25, 2026

Abstract

GP5+M+N achieved a humoral immune response comparable to a commercial inactivated vaccine while inducing significantly higher levels of IFN-γ secretion.

Multiple mRNA constructs encoding PRRSV structural proteins were developed and tested for their immunogenicity in mice.
The combination of GP5+M+N not only matched the immune response of the inactivated vaccine but also provided effective protection in piglets.
GP5+M+N induced a stronger specific antibody response and enhanced cellular immune response compared to the GP5MN fusion protein.
The cellular immune response from the GP3+GP4+GP5 combination was significantly better than that from the GP345 fusion protein.
The findings support the potential of mRNA vaccines for PRRSV and suggest that using individual antigen mRNAs is more effective than using combined antigen fusions.

Simplified

Porcine reproductive and respiratory syndrome virus (PRRSV) has caused significant economic losses in the livestock industry. Due to high genetic variability and limited cellular immunity induction by traditional vaccines, current options offer insufficient protection. In contrast, mRNA vaccines offer flexibility in antigen design and enhanced cellular immune response, presenting a promising solution for PRRSV vaccination. In this study, multiple mRNAs encoding PRRSV structural proteins GP3, GP4, GP5, M, and N, as well as the fusion proteins GP345 and GP5MN, were constructed, encapsulated in lipid nanoparticles (LNPs), and administered to mice either with individual fusion protein mRNA-LNPs or a combination immunization of structural protein mRNA-LNPs formulations to evaluate their immunogenicity in vivo. To further assess protective efficacy, we compared GP5+M+N and GP3+4+5 with a commercial inactivated vaccine in piglets. Notably, GP5+M+N not only achieved a humoral immune response comparable to that of the inactivated vaccine but also induced significantly higher levels of IFN-γ secretion and conferred effective protection in piglets. The results showed that GP5+M+N could induce a stronger specific antibody response and cellular immune response than GP5MN; the cellular immune response induced by GP3+GP4+GP5 (GP3+4+5) was also significantly better than that of GP345. These results not only verified the application potential of PRRSV mRNA vaccines but also indicated that the combination immunization of mRNAs expressing individual antigens was superior to that of mRNAs expressing multiple antigen fusions. This study provides both theoretical support and practical guidance for the rational design of PRRSV mRNA vaccines.

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Competing interests

Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

PubMed

Combining mRNA vaccines for PRRS virus boosts immune defense and protection in piglets

Abstract

Full Text

Funding

Competing interests

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