Pilot-scale production of a highly efficacious and stable monoglycosylated influenza split virus vaccine.

• Optimizing and scaling up the monoglycosylated vaccine production process for clinical trials and future product development. • IVR-190 mg presents comparable stability with fully glycosylated IVR-190 virus vaccine. • IVR-190 mg induced substantial cross-strain HA- and NA-inhibiting antibody responses. • Toxicology study provides safety profiles for IVR-190 mg for further clinical study. The yearly epidemics and unpredictable outbreaks of influenza have raised serious concerns globally and led to prioritizing the development of an effective vaccine to protect against newly emerging variants. Previously, we demonstrated that monoglycosylated influenza virus vaccines derived from A/California/7/2009 or an updated A/Brisbane/02/2018 (IVR-190) vaccine strain recommended by WHO are superior to fully glycosylated vaccines and could broadly protect against past and new coming H1N1 variants. However, whether such a monoglycosylated virus vaccine can be mass-produced to meet clinical demands and stable enough to provide consistent efficacy against H1N1 viruses remains unclear. Herein, we developed a platform for the pilot-scale production of the monoglycosylated split virus vaccine from the IVR-190 strain (IVR-190 mg) with a robust and cost-effective manufacturing process. The critical parameters of inoculum dose, concentration of kifunensine, and optimized Endo H treatment process were comprehensively investigated. Several aims for preclinical studies of IVR-190 mg were achieved, including [i] the execution of three engineering batch runs to validate lot-to-lot consistency, [ii] the establishment of IVR-190 mg specifications to meet the acceptance criteria of a conventional influenza vaccine, [iii] an investigation of the stability profile of IVR-190 mg , and completion of a safety evaluation by conducting an animal toxicology study. The toxicology study under GLP guidance found no systemic toxicity after rabbits were vaccinated with IVR-190 mg. The serological data showed that IVR-190 mg is highly immunogenic and effective in inducing a cross-strain protective level of antibody immune responses, including hemagglutination-inhibition titers, viral neutralization activity, and broad HA- and NA-inhibiting antibody titers against past and new H1N1 viruses. In conclusion, this study provides efficacy and safety profiles of IVR-190 mg for further clinical study and shows that this vaccine without a glycan shield has great potential to be safe and protective against H1N1 variants. [ABSTRACT FROM AUTHOR]