Sustained superior humoral immune responses of mRNA vaccines compared to Sputnik V viral vector COVID-19 vaccines in naïve and convalescent populations.

BACKGROUND

The choice of vaccine platform fundamentally influences the magnitude and durability of antibody responses against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We compared humoral immune responses between BNT162b2/mRNA-1273 (mRNA) and Sputnik V (adenoviral vector) vaccines across multiple timepoints.

METHODS

Anti-ancestral (WT) spike binding antibodies were measured by enzyme-linked immunosorbent assay (ELISA) and neutralizing antibodies by microneutralization assay using live SARS-CoV-2 WA.1 strain. Sera from 48 naïve and 24 convalescent study participants were collected prior and after the primary immunization (mRNA: 28; Sputnik V: 44).

RESULTS

mRNA vaccines elicited higher binding antibody responses (p < 0.001 in naïve, p < 0.05 in convalescent participants) and neutralizing antibody responses (p < 0.001 in naïve participants) compared to Sputnik V. Antibody decay kinetics were similar between platforms (half-life ∼5 months), with mRNA vaccines maintaining sustained superiority through 6 months post-vaccination.

CONCLUSIONS

mRNA vaccination provides markedly superior and sustained antibody responses compared to adenoviral vector vaccine, which is particularly relevant for long-term protection strategies.