Presentation (CTI)

OBJECTIVES: Vaccination programmes deliver clinical and economic benefits, yet their environmental value remains unquantified. Healthcare systems contribute approximately 4-5% of global greenhouse gas (GHG) emissions, with care pathways, including surgery, radiotherapy, chemotherapy, and patient travel, representing a meaningful share of this burden. Preventive interventions that reduce disease incidence offer potential environmental co-benefits alongside health. The human papilloma virus (HPV) vaccination substantially reduces cervical cancer and cervical intraepithelial neoplasia (CIN3) incidence, yet GHG emissions avoided have not been quantified. This research aims to estimate GHG emissions associated with cervical cancer and CIN3 care pathways in England, and quantify emissions avoided under observed HPV vaccination versus a counterfactual unvaccinated scenario.
METHODS: Published estimates of cervical cancer (n=687) and CIN3 (n=23,192) cases prevented through HPV vaccination in England by June 2020 were used to parameterise an environmental model comparing GHG emissions under vaccinated and counterfactual unvaccinated scenarios. Care pathways were mapped by disease stage using published clinical guidance. Stage IV was limited to first-line treatment due to subsequent heterogenous management. GHG emissions were assigned to surgery, inpatient stay, outpatient treatment, radiotherapy/chemotherapy sessions, and patient travel using Sustainable Healthcare Coalition emission factors. Emissions were calculated per patient and across the modelled population.
RESULTS: Total cervical cancer treatment emissions decreased from 380,254kg carbon dioxide equivalents (CO₂e) for those unvaccinated to 202,423kg CO₂e for vaccinated patients, avoiding 177,832kg CO₂e (-46.8%).The largest absolute reduction occurred in stage IB/IIA disease, avoiding 135,588kg CO₂e, followed by stage IIB/III/IVA with 32,612kg CO₂e. Total CIN3-related emissions decreased from 1,465,187kg CO₂e to 736,958kg CO₂e, avoiding 728,229kg CO₂e (-49.7%). Total average per-patient emissions were 31.4kg CO₂e for CIN3 and 259.1kg CO₂e for cervical cancer.
CONCLUSIONS: HPV vaccination substantially reduces healthcare-related GHG emissions by mitigating the need for cervical cancer and CIN3 treatment. These findings highlight an additional environmental value of vaccination programs beyond clinical and economic benefits.