Novel multiplex tools in an epidemic panel improve prediction of RSV infection dynamics and disease burden a RESPINOW analysis

Respiratory Syncytial Virus (RSV) is one of the leading causes of morbidity and mortality among infants and adult risk groups worldwide. Substantial case-underdetection and gaps in the understanding of reinfection dynamics of RSV limit reliable projection estimates. Here, we use a novel RSV multiplex serological assay in a population-based panel to estimate season and age-specific probability of reinfection and combine it with sentinel and notification data to parameterize a mathematical model tailored to project RSV dynamics in Germany from 2020 to 2023. Our reinfection estimates, based on a 20% post-F and a 45% N antibody increase in the assay over consecutive periods, were 5{middle dot}7% (95%CI: 4{middle dot}7-6{middle dot}9) from 2020 to 2022 and 12{middle dot}7% (95%CI: 10{middle dot}5-15{middle dot}2) from 2022 to 2023 in adults. In 2021, 30-39 year olds had a higher risk of reinfection, whereas in 2022, all but the 30-39 age group had an increased risk of reinfection. This suggests age-differential infection acquisition in the two seasons, e.g. due to still stronger public health measures in place in 2021 than in 2022. Model-based projections that include the population-based reinfection estimations predicted the onset and peak for the 23/24 RSV season better than those only based on surveillance estimates. Rapid, age-specific reinfection assessments and models incorporating this data will be critical for understanding and predicting RSV dynamics, especially with changing post-pandemic patterns and new prevention strategies e.g. monoclonal antibody. Helmholtz Association, EU Horizon 2020 research and innovation program, Federal Ministry of Education and Research, and German Research supported this work.