Science Research Evidence: winter modelling 2025 to 2026 - Part 10: conclusions

The upcoming 2025 to 2026 winter season is expected to see a rise in respiratory viruses, as is typical each year. This leads to higher demand on primary (GP consultations) and secondary care services (admissions, ED attendances etc). The scenarios in this paper give an insight into how these viruses may impact the demand for healthcare in Wales and help in planning for a surge in capacity that might be needed to accommodate these excess winter pressures.

Vaccination programs are crucial in preventing infectious diseases. The RSV vaccination program was launched in September 2024, and the year-long program will continue through September 2026. High uptake is expected to significantly reduce admissions among infants (1 to 6 months) and adults (75 to 79 years). COVID-19 admissions are declining. The modelling in this report estimates earlier impact this winter. Flu vaccine uptake has decreased since 2021 to 2022, which, if the trend continues, may place additional strain on hospital admissions. The antigenicity of circulating influenza strains remains a critical factor influencing the severity of the flu season, although it is challenging to predict accurately. As a result, it's difficult to determine how severe each flu season will be.

Over the winter months (1^st September to 31^st March), there will be continued surveillance of admissions due acute respiratory viruses. The winter modelling scenarios presented in this report will be utilised alongside short-term projections, which will be updated as additional data are collected throughout the winter and presented in regular surveillance reports. Collectively, these models will serve as effective tools to support decision-making in healthcare planning across Wales.