Assessment of Viral Vaccine N-Glycosylation via Orthogonal Capillary Electrophoresis-Based Methods

Despite global vaccination programs, seasonal influenza continues to pose a significant economic burden and strain on healthcare systems worldwide. Annual reformulation of influenza vaccines is required due to the high mutation rates of surface glycoproteins on influenza viruses. Although vaccination is the most effective preventative measure against influenza viruses, reduced vaccine efficacy in recent years has become an increasing concern. Egg-adaptations incurred through the manufacturing process of influenza vaccines result in antigenic mismatches, whereby vaccine strains differ from the wild-type circulating viruses. In 2017, low vaccine efficacy was attributed to altered glycosylation characteristics of the H3N2 vaccine strain whereby an egg-adaptation resulted in the deletion of a single N-glycosylation site. However, even with these implications on immunogenicity, influenza glycosylation is not a well-implemented critical quality attribute and therefore not optimally controlled or regulated during vaccine manufacturing due to assay limitations.