Currently, some countries using vaccines against avian influenza have mechanisms in place to monitor antigenic changes in field strains. However, this information is not always shared internationally or made publicly available. The goal of the OFFLU Avian Influenza Matching Project (OFFLU-AIM) is to provide improved information on antigenic characteristics of avian influenza viruses to support vaccination programmes against the disease.

Effectiveness of vaccination of poultry against high pathogenicity avian influenza (HPAI) depends on usage of appropriate vaccines at the recommended doses and age. Antigenic variation in field strains may render vaccines less effective. This is particularly true for vaccines that depend primarily on the humoral immune response, such as killed antigen (inactivated) adjuvanted vaccines.

OFFLU-AIM provides information on possible antigenic changes in HPAI viruses that could reduce effectiveness of vaccination programmes unless timely updates of vaccines occur.

The project also assists countries utilising vaccines to stay knowledgeable about potential changes in the antigenic characteristics of circulating strains. This information is also of value for countries considering introduction of vaccination as an additional preventive and control measure.

The information in this report is derived from multiple sources including antigenic studies conducted at OFFLU reference laboratories. It focuses on goose/Guangdong/1/96-lineage A(H5Nx) viruses (gsGD).

Access the OFFLU-AIM report here

More information: OFFLU – WOAH/FAO network of expertise on animal influenza (www.offlu.org)

Contact: Gounalan Pavade, OFFLU Secretariat (secretariat@offlu.org)