OBJECTIVES: The healthcare system accounts for ~4% of total United Kingdom (UK) carbon emissions every year. As a response to climate change, the National Health Service has committed to achieving net zero by 2040 and is calling for less carbon-intensive care practices, including prevention. Respiratory Syncytial Virus (RSV) is a leading cause of infant hospitalization against which there is currently no widespread immunization program in the UK. This study estimates the impact on carbon emissions generated within the direct patient care pathway from a new monoclonal antibody immunization, nirsevimab, against RSV.

METHODS: A novel approach was applied, mapping patient care pathway emissions from both immunization and avoided RSV primary and secondary care burden. Avoided healthcare resources were estimated using a published health economic model for nirsevimab vs. standard care (SoC) characterized as palivizumab or no intervention, assuming different infant population size scenarios. UK-specific carbon emission factors from the NHS, which include visitor and patient travel, were applied to each health outcome to measure the carbon emissions associated with a nirsevimab vs. SoC strategy.

RESULTS: All scenarios considered lead to significant carbon savings (2 kt to 22kt CO₂eq per year). The scenario leading to greatest avoided carbon emissions included immunizing all infants at birth, which is equivalent to 34 kg CO₂eq avoided per immunized infant. Immunizing at birth or within existing national immunization program touchpoints limited emissions from immunization. The largest sources of emissions avoided were from reduced primary care visits and inpatient hospitalizations, which together account for ~18kt CO₂eq avoided out of 22kt.

CONCLUSIONS: This novel approach shows how prevention can deliver co-benefits to healthcare systems. However, emissions avoided from the direct patient care pathway must be put in the context of emissions from production, distribution and disposal of the drug which are not considered here.