Multiplex serology reveals age-specific immunodynamics of respiratory pathogens in the wake of the COVID-19 pandemic.

Summary

Using a quantitative multiplex serology platform, the study shows children under five mount larger but faster-waning antibody responses across multiple respiratory viruses compared to older individuals. Validation in a separate pre-pandemic cohort and model calibration suggest age-specific immunodynamics are critical to forecasting post-pandemic epidemic patterns and guiding vaccination strategy.

Key Findings

• Children <5 years exhibited larger antibody boosts but faster waning across influenza, RSV, seasonal coronaviruses, and SARS-CoV-2.
• Findings were validated using pre-pandemic influenza serology from South Africa (n=1028).
• An influenza transmission model incorporating age-specific immunodynamics improved forecasts of post-pandemic epidemic patterns.

Clinical Implications

Age-specific waning should inform vaccine schedules (timing/boosters) and surveillance thresholds, especially in young children who exhibit rapid decline after strong boosts.

Limitations

• Serology reflects humoral immunity; cellular responses were not directly measured
• Generalizability beyond studied geographies requires further validation

Future Directions

Extend to cellular immunity, link antibody kinetics to clinical protection, and test optimized age-stratified vaccination schedules in prospective studies.