Nirsevimab is a monoclonal antibody developed as a passive immunization strategy to prevent lower respiratory tract infection (LRTI) caused by respiratory syncytial virus (RSV) in all infants experiencing their first RSV season

Dynamic mathematical models can provide initial insights into the direct and indirect effects of nirsevimab on RSV transmission, taking into account the uncertainties surrounding its mechanism of action

We used a deterministic, age-structured, compartmental RSV transmission model to assess the potential impact of nirsevimab on the prevention of medically attended LRTI caused by RSV in the overall population in the USA, with an unprecedented level of granularity in age groups < 2 years

The model showed significant benefit of prophylactic nirsevimab on RSV when administered to all infants during their first season; this benefit increased upon assumption of an effect of nirsevimab on viral shedding

These preliminary data suggest that single-dose nirsevimab may provide considerable benefit to infants experiencing their first RSV season