Table 1.
Antigens and antisera used in this study.
| Name | HA protein | Relevant AIV strain | Application | Origin |
|---|---|---|---|---|
| rH5-E. coli | aa 17–522 ΔRRRKKR | A/swan/Poland/305-135V08/2006(H5N1) | Vaccine antigen tested in broiler (Exp 1) and layer chickens (Exp 2) | IBA |
| rH5-BEVS | aa 17–530 ΔRRRKKR 6x His | A/swan/Poland/305-135V08/2006(H5N1) | Reference antigen in rH5-E. coli analyses and broiler chicken vaccinations (Exp 1); antigen in H5 iELISA | OET |
| rH5-mammalian | aa 17–530 ΔRRRKKR 6x His | A/Bar-headed Goose/Qinghai/12/05(H5N1) | Reference antigen in rH5-E. coli analyses | ITC |
| H5N2 LPAIV | Full-length | A/turkey/Italy/80(H5N2) | Antigen in the HI test | x-OvO Ltd. IZSVe |
| Anti-H5N2 LPAIV antiserum | Full-length | A/turkey/Italy/80(H5N2) | Positive control in the HI test | x-OvO Ltd. IZSVe |
| Anti-H7N4 LPAIV antiserum | Full-length | A/mallard/Italy/4810-79/04(H7N4) | Negative control in the HI test | x-OvO Ltd. IZSVe |
| Anti-H7N7 LPAIV antiserum | Full-length | A/macaw/England/626/80(H7N7) | Negative control in the HI test | x-OvO Ltd. IZSVe |
Recombinant H5 hemagglutinin antigens, rH5-E. coli, rH5-BEVS, and rH5-mammalian, were produced in bacterial, baculoviral, and mammalian expression systems at the Institute of Biotechnology and Antibiotics (IBA; Warsaw, Poland), Oxford Expression Technologies Ltd. (OET) and Immune Technology Corporation (ITC), respectively. The low-pathogenic avian influenza virus (LPAIV) and anti-LPAIV antisera, certified by Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), were purchased from x-OvO Ltd.