On the highly pathogenic avian influenza (HPAI) front, the European Food Safety Authority (EFSA) will issue a new scientific opinion, which is expected to be finalized in March 2024. The European Commission has requested an overview of the available HPAI vaccines , their effectiveness against currently circulating viruses and an evaluation of various vaccination schemes to guide decisions on possible vaccination strategies. EFSA was also tasked with evaluating surveillance and risk mitigation measures in vaccinated areas and farms.

Data on the efficacy of protection and duration of protection of available vaccines against HPAI are few and not harmonized; therefore, detailed description and comparison of these vaccines is not possible. Few vaccines are tested on bird species other than chickens. Field studies on the effectiveness of vaccination in stopping transmission of the virus are scarce. Updated information on the types and characteristics of vaccines available against HPAI has been provided.

In the European Union there is only one authorized vaccine against HPAI in chickens. Insights were provided on different vaccination strategies for the control of HPAI in poultry, i.e. emergency protective vaccination in areas surrounding an HPAI outbreak and preventive vaccination in areas and flocks where the infection is not still present. Recommendations for future scientific studies on HPAI vaccines were provided.

EFSA's scientific advice on HPAI vaccines and vaccination strategies will inform policy makers and risk managers in European Union Member States on potential HPAI prevention and control strategies, thus enabling informed decisions on the prevention of HPAI. disease and epidemic control. EFSA's opinion could guide the future development and use of vaccines against HPAI.

Preventive vaccination is considered by EFSA to be the optimal vaccination strategy to minimize the number of outbreaks and the duration of the epidemic and should be carried out in the most sensitive and infectious poultry species in areas with high risk of transmission. To increase protection, multiple administrations (i.e. booster vaccinations) can be used.

In the event of an epidemic, EFSA recommends emergency protective vaccination within a 3 km radius of the epidemic in areas with high risk of transmission. Vaccine efficacy should be monitored for all vaccination strategies. Vaccination should complement and not replace other preventive and control measures, such as infection monitoring in birds, early detection and biosecurity, and is recommended as part of an integrated disease control approach. The scientific opinion includes recommendations for future scientific studies on Hpai vaccines in terms of the types of vaccines to be developed and for which bird species, aspects of the vaccines that should be studied and the type of studies that should be conducted.