National flu immunisation programme plan 2026 to 2027 26.2.2026 | Her Majesty's Revenue and Customs The annual flu letter describes the national flu immunisation programme and outlines which groups are eligible for flu vaccination. The annual flu letter for 2026 to 2027 describes the national flu immunisation programme and outlines which groups are eligible for flu vaccination. Annual letters for previous years can be found at: 2025 to 2026 2024 to 2025 2023 to 2024 2022 to 2023 2021 to 2022 2017 to 2018, to 2020 to 2021 Published 13 February 2025 https://www.gov.uk/government/publications/national-flu-immunisation-programme-plan-2026-to-2027