Defra has begun 24-week field trials of highly pathogenic avian influenza (HPAI) vaccines in England today, Thursday 5 March 2026. The pilot focuses on turkeys only and is designed to answer the commercial questions that matter: do the latest vaccines protect birds in real farm settings, can surveillance keep trade moving, and will this reduce the £174m annual hit that outbreaks impose on government and industry?

Under approvals from the Veterinary Medicines Directorate, a small cohort of turkeys will be vaccinated using UK/EU‑authorised products and monitored under strict supervision. Routine poultry vaccination against bird flu remains prohibited in the UK; this work is tightly controlled to generate the data ministers, buyers and exporters need before any policy shift.

The UK and Europe have endured unprecedented waves of H5N1 since 2020, forcing mass culls and disrupting supply. For farmers and processors, that has meant volatile throughput, biosecurity costs and difficult staffing decisions around sudden standstills. Defra’s statement puts the combined annual cost to government and industry at up to £174m, a figure that does not capture the knock‑on effects on logistics and retail promotions.

Turkeys have been chosen because they are acutely susceptible to HPAI, with outbreaks producing severe clinical signs and rapid, high mortality. That susceptibility makes the species a useful early indicator of whether vaccination can meaningfully cut infection and onward spread, and therefore reduce the scale of pre‑emptive culls that ripple back through hatcheries, feed mills and abattoirs.

Officials are clear that vaccination, if proven effective, would sit alongside rather than replace biosecurity. The UK Chief Veterinary Officer, Christine Middlemiss, has framed the trial as crucial to understanding how vaccines could be used for disease control, while stressing rigorous on‑farm hygiene as the first line of defence. Biosecurity Minister Baroness Hayman describes the programme as a step forward for biosecurity and food supply, aligned with wider international research. APHA scientist Professor Ashley Banyard has highlighted that measuring immune response in turkeys will be a strong signal of suitability against H5N1.

Trade is the tightrope. Export partners need confidence that vaccinated flocks are disease‑free, which places surveillance and testing methodology at the centre of the trial. The programme will examine how monitoring can differentiate infection from vaccination and sustain market access for poultry meat and breeding stock, issues that weigh heavily on integrated processors and their lenders.

The timetable matters for planning. Starting on 5 March, the 24-week trial runs into late August 2026, after which the HPAI vaccination taskforce is expected to draw on the findings for final recommendations. That means any practical policy changes would land, at the earliest, after the summer, giving producers a window to scenario‑test autumn and Christmas placements under both vaccinated and non‑vaccinated assumptions.

For balance sheets, a workable vaccine could reduce the frequency of catastrophic culls and the associated write‑offs in live bird inventories, overtime in processing, disposal costs and lost retail contracts. Even a modest fall in outbreak severity could steady cash flows for SMEs that supply feed, transport and packaging into the poultry chain, where margin pressure has been acute.

Until then, the guidance is unchanged: stringent biosecurity remains the best defence. Defra and the Animal and Plant Health Agency continue to urge bird keepers to maintain separation between flocks and wild birds, control movements on and off site, watch for symptoms and report promptly. Compliance today is also what will make any future vaccination programme credible to trading partners.

The UK trial sits alongside work in Italy and the Netherlands, as countries confronting similar risks test whether vaccination can be integrated without undermining surveillance. The shared goal is clear: protect birds, keep trade open and provide farmers and processors with a more predictable operating environment.

In July 2025, the UK’s HPAI Vaccination Taskforce published a report setting out the status and challenges of poultry vaccination, including a cost‑benefit analysis and the recommendation for a domestic turkey field trial. Today’s launch implements that advice and will add evidence to the growing international research base.