Impact of Inactivated SARS-CoV-2 Vaccines on Serum Glycan Profiles and Protein N-Glycosylation.

BACKGROUND

This study aimed to investigate the effect of inactivated SARS-CoV-2 vaccines and booster shots on serum glycan profiles and protein N-glycosylation, specifically how vaccination influences glycan synthesis over time, how booster shots differentially impact populations with varying antibody titers, and which specific glycoproteins exhibit altered glycosylation. The goal was to explore a novel mechanism by which COVID-19 vaccines might exert antiviral effects through indirect inhibition of host glycosylation.

METHODS

Serum glycan profiles were analyzed in individuals receiving two primary doses and a booster shot of in-activated SARS-CoV-2 vaccine, categorized by symptomatic status and antibody titers. Serum proteins were immobilized on AminoLink plus coupling resin, followed by sequential derivatization of α2,6- and α2,3-linked sialic acids. Glycans were released using PNGase F and analyzed by MALDI-TOF-MS with maltoheptaose as an internal standard. Glycoproteomics via LC-MS/MS identified site-specific protein glycosylation changes.

RESULTS

Significant alterations in serum glycan profiles were observed. Overall glycan synthesis showed substantial suppression one-month post-vaccination, followed by gradual recovery. The booster vaccine inhibited glycan synthesis, and high-titer individuals exhibited a more pronounced N-glycan profile and faster recovery. Symptomatic status had no significant impact on glycan abundance. Glycoproteomic analysis revealed substantial alterations in glycosylation of stress and immune response proteins, including CP, HPX, SERPINA1, FN1, IgG, AGP, and C3, after vaccination.

CONCLUSIONS

This study demonstrates a novel mechanism: inactivated COVID-19 vaccines indirectly inhibit host glycosylation pathways. Vaccination significantly suppresses N-glycosylation, primarily reducing N-glycan abundance, with recovery influenced by antibody titer. These results highlight the intricate relationship between immune response, host glycosylation, and viral infection, suggesting avenues for developing novel therapeutic strategies targeting both the virus and host response to enhance antiviral protection.