Longevity & AgingGlycan Masking Helps an Experimental COVID Vaccine Neutralize More Variants
Adding a sugar attachment site to an experimental COVID-19 vaccine antigen improved its ability to generate virus-neutralizing antibodies in guinea pigs. Researchers modified the receptor-binding domain of the SARS-CoV-2 XBB.1.5 spike protein to mask a region associated with antibody binding but not neutralization. Animals received two mRNA vaccine doses, and their blood was tested against 19 spike-bearing pseudoviruses. Compared with the unmodified antigen, the modified version significantly increased neutralization against 10 variants, including several immune-evasive Omicron lineages. The largest reported improvements were 6.4-fold for JN.1 and 5.7-fold for BA.2. The findings support redirecting immune responses toward more useful targets rather than simply updating vaccine sequences. However, this was an animal laboratory study, not evidence of protection in humans, and longer-lasting immunity was not demonstrated.
