A lyophilized stabilizer formulation enhances thermostability and preserves the immunogenicity of Senecavirus A post thermal challenge.

Senecavirus A (SVA) is a pathogenic virus that causes vesicular lesions, locomotor disorders, and neonatal mortality in pigs. Its increasing global prevalence poses a persistent threat to the swine industry. Vaccination remains the primary control strategy; however, SVA exhibits pronounced thermal instability, and exposure to unsuitable temperatures during storage or transport can impair vaccine immunogenicity. We developed a heat-stable lyoprotectant formulation for live SVA vaccines to overcome this limitation. The formulation, composed of 10% trehalose, 2% inulin, 2% dextran 40, 2% mannitol, 2% polyethylene glycol, 5% tryptone, 1% glycine, and 1% gelatin, demonstrated superior preservation during lyophilization and significantly greater thermal stability than conventional skim milk protectants. It exhibited no cytotoxicity at a 10% concentration and induced strong neutralizing antibody responses in mice, even after heat exposure. Collectively, this study establishes an effective lyoprotectant formulation that enhances the thermal stability and immunogenic integrity of live SVA, offering a practical advancement for improving vaccine quality and field efficacy.