Advancing vaccine development: Evaluation of a mannose-modified lipid nanoparticle-based candidate for African swine fever p30 mRNA vaccine eliciting robust immune response in mice.

The African swine fever virus (ASFV) continues to pose significant economic and pandemic risks. Consequently, discovering new, efficient vaccines is crucial. Messenger RNA (mRNA) vaccines have emerged as promising candidates, providing minimal risk of insertional mutagenesis, high safety profiles, effectiveness, rapid scalability in production, and cost-effectiveness. In this study, we have developed an ASF p30 mRNA vaccine candidate (mRNA/Man-LNP) employing mannose-modified lipid nanoparticles (LNPs). The mRNA/Man-LNP exhibited effective antigen presentation and facilitated dendritic cells (DCs) maturation. Notably, it elicited strong IgG titers and activated CD4+ and CD8+ T-cells in immunized mice, all while adhering to stringent biosafety standards. This investigation demonstrates that mRNA/Man-LNP can trigger both humoral and cellular immune responses, suggesting its potential as a potent and promising vaccine candidate for controlling African swine fever (ASF).

Development and validation of an insulated isothermal polymerase chain reaction assay for the rapid detection of Mycoplasma synoviae.

Mycoplasma synoviae, which causes the disease known as chicken synovitis, causes serious immunosuppression. We developed a rapid insulated isothermal polymerase chain reaction (iiPCR) assay for on-site detection of M. synoviae using a primer and probe set targeting the variable lipoprotein and haemagglutinin (vlhA) gene. In addition, the specificity, sensitivity, repeatability, and clinical detection of this method were evaluated. Our iiPCR assay detected M. synoviae clinical isolates and samples successfully and produced negative results on Mycoplasma galliscepticum, avian viral arthritis, Escherichia coli, Salmonella, Staphylococcus aureus and Corynebacterium, indicating that the PCR reactions were specific. Additionally, our iiPCR assay detected the prepared positive standard plasmid diluted 10 times (1.00 × 10-1 - 1.00 × 10-10) as a template. The undiluted positive plasmid was positive and double distilled water was negative indicating that the PCR reactions were sensitive, respectively. Finally, the vlhA positive standard plasmid with dilution multiple of 1.00 × 10-4 - 1.00 × 10-6 was repeatedly detected three times to evaluate the repeatability of the iiPCR method established in this experiment showing that the iiPCR of M. synoviae is repeatable. The established iiPCR was also used to detect 50 chicken joint enlargement samples. The thermostatic detection PCR established in this experiment was comparable to a reference real-time PCR (qPCR).