Science Research Evidence: winter modelling 2025 to 2026 - Part 3: headline results

Influenza (flu) admissions and occupancy (International Classification of Diseases 10 (ICD-10) codes: J09-J11)

Winter 2024 to 2025: Wales experienced the highest total number of winter flu hospital admissions since the pandemic, though peak daily admissions (78) were lower than in 2022 to 2023 (109). Bed occupancy due to flu peaked at 487 beds, more than twice the peak of the winter before (2023 to 2024), but less than the 2022 to 2023 peak (602 beds).

2025 to 2026 modelling scenarios: a peak of 51 to 78 daily admissions is estimated in early January 2026 (low to high scenarios), and 109 admissions in late December 2025 under a severe scenario. A peak of 153 to 487 beds (on the 6 to 7 January 2026) is estimated in the low, moderate and high scenarios. A peak of 602 beds is estimated to occur in the last week of December in the severe scenario.

Paediatric admissions and occupancy (0 to 4 years)

Winter 2024 to 2025: age groups 1 to 6 months, 7 to 12 months and 1 to 4 years showed a decrease of 33%, 26% and 14% RSV admissions respectively compared to the 2023 to 2024 season. The greater reductions among the youngest age groups may reflect the temporary protection effects of the maternal vaccination. Bed occupancy peaked at 29 beds on 30 November 2024, lower than the peak of 2023 to 2024 winter (33 beds).

2025 to 2026 modelling scenarios: peaks of 16 to 18 daily admissions are estimated (18 to 19 November for the low season scenario, 8 to 11 December for the high season scenario). A peak demand of 43 to 45 beds is estimated to occur (8 to 12 December 2025) in high season scenarios and 39 to 42 beds (19 to 20 November 2025) for low season scenarios.

Admissions and occupancy in older adults (75+)

Winter 2024 to 2025: there were 224 RSV admissions in adults aged 75 years and above last winter (2024 to 2025), which was 64% higher than the previous winter (2023 to 2024) and 35% higher than the average of the past 3 years (2021 to 2022, 2022 to 2023, 2023 to 2024). When considering those eligible for the vaccine (75 to 79 year olds), there was a 19% increase in RSV admissions last year (2024 to 2025 winter) compared with the prior winter (2023 to 2024). However, there was a 10% decrease observed in this age group when comparing with the average number of RSV admissions over the past 3 years. This may be due to the vaccine or natural seasonal variation. We may not see the full effects of the vaccine until the coming winter (2025 to 2026). Bed occupancy for adults aged 75 and above peaked in the third week of January at 54 beds per day, almost 3 times higher than the previous winter (2023 to 2024).

2025 to 2026 modelling scenarios: For adults aged 75 to 79, the high season occupancy scenarios (based on the 2022 to 2023 winter) with Vaccine Uptake (VU) of 30% and 60%, indicate a projected peak of 10 to 13 beds between 30 December 2025 to 2nd January 2026, while low season occupancy scenarios (based on the 2023 to 2024 winter) with VU= 30% and VU= 60% estimate 2-3 beds (1 to 2 December 2025).

Winter 2024 to 2025: there were 2,228 admissions, a decrease compared to 4,248 admissions in 2023 to 2024. There was a peak of 25 daily admissions in the first week of October. The peak and totals for daily bed occupancy due to COVID-19 has decreased each year since the height of the pandemic (in 2020 to 2021).

2025 to 2026 modelling scenarios: the low and moderate scenarios estimate peaks of 10 and 25 daily admissions respectively. The severe scenario estimates a double peak, of 40 admissions on 3rd October 2025 and 34 on 3rd January 2026.The severe occupancy scenario estimates a maximum of 542 beds required on 13 October. The moderate and low scenarios project peaks of 339 and 164 beds on 15 October and 20 October, respectively.

The severe combined admissions modelling scenario anticipates a peak of 296 admissions on 24 December 2025, whereas the moderate scenario estimates a maximum of 214 admissions on the same day.

The severe combined occupancy scenario estimates a peak of 2,443 occupied beds on 5 January 2026, whereas the moderate scenario estimates a maximum of 1,885 beds occupied on 7 January 2026.

Emergency Department (ED) attendances

Last winter (2024 to 2025), there were 51,790 ED attendances due to respiratory problems - more than the previous two years. ED attendances due to respiratory problems peaked at 343 in the first week of January 2025.

The low modelling scenario estimates a peak of 264 ED attendances on 1 January 2026, while moderate and severe modelling scenarios predict a peak of 312 and 417 ED attendances on 30th December 2025.

Capacity and resilience

During the winter of 2024 to 2025, average daily bed numbers ranged from 10,260 to 10,670, with occupancy ranging between 84 to 87%. The percentage of beds occupied has remained relatively stable over the past two winters, consistently above 80% but never exceeding 90%.

GP consultation rate

Last winter (2024 to 2025), adults and children had fewer GP consultations due to acute respiratory infections (ARI) compared to the 2023 to 2024 winter.

The daily average GP consultation rate during winter 2024 to 2025 for children (aged 14 or younger) was higher than that for adults (aged 15 and above), with 47 consultations per 100,000 population for children compared to 17 consultations per 100,000 for adults.

The severe, moderate, and low scenarios for GP consultation rates in children are estimated to reach maximum values of 369, 138, and 54 consultations per 100,000 population on 9 to 11 December, 17 December, and 26 December, respectively.

The projected peak of GP consultation rates for adults under the severe, moderate, and low scenarios are 106, 46, and 16 consultations per 100,000 population, occurring on 30 Dec to 2nd January and 27 December and 26 December, respectively.

Flu

Flu vaccine uptake rates in adults aged 65 and above has decreased each year from 78% in 2021 to 2022 to 70% by the end of the 2024 to 2025.

The vaccine uptake in those ‘at risk’ aged 6 months to 64 years has also decreased over the same period from around 48% at the end of the 2021 to 2022 season to 37% at the end of the 2024 to 2025 season.

However, the total number of flu vaccines administered in the 2024 to 2025 winter (651,455) to all eligible groups is still higher than the number of flu vaccines administered the year before the pandemic (642,284 in 2019 to 2020).

RSV

As noted in Public Health Wales' RSV vaccination report and of 28 August 2025, the RSV vaccine uptake rate was 48% in pregnant women and 62.9% amongst adults aged 75 to 79.

In Wales, vaccine uptake rates in older adults may be similar to those in England but comparatively lower than in Scotland across both older adults and pregnant women.

COVID-19

The COVID-19 Vaccine uptake among individuals aged 75 and above, and the immunocompromised has declined each year since 2021 to 2022.