Conjugate vaccine technology enhances responses to influenza virus.

Influenza remains a major public health concern due to its high mutation rate and the limited efficacy of current seasonal vaccines. Traditional subunit and inactivated virus vaccines often elicit strain-specific responses and fail to generate long-lasting or broadly protective immunity. To address these limitations, we utilized the iBoost platform, a conjugate vaccine strategy based on a chimeric designer peptide (CDP) derived from bacterial immunogens, to enhance immune responses against influenza virus antigens. Using hemagglutinin (HA) and neuraminidase (NA) constructs from the A/Wisconsin/588/2019 (H1N1) strain, we developed CDP-H1 and CDP-N1 vaccine candidates and assessed their immunogenicity in murine models. Compared to unconjugated counterparts, CDP-fused constructs induced significantly stronger and more rapid antibody responses, with broader IgG subclass distribution and higher IgG2a levels, potentially indicative of enhanced effector functions. CDP-H1 elicited measurable HA-inhibiting activity by hemagglutination inhibition (HAI) assay and demonstrated partial binding cross-reactivity to heterologous H1 and H3 strains, while CDP-N1 induced antibodies with cross-reactive potential to N2. These preliminary findings suggest that iBoost may enhance both the magnitude and quality of humoral responses, supporting its potential as a platform to improve the breadth and kinetics of antibody induction. However, further studies incorporating functional and in-vivo challenge assays will be required to confirm protective efficacy and validate the translational potential of this approach.