Highly pathogenic avian influenza (HPAI) clade 2.3.4.4B H5N1 viruses are circulating in birds and cows and have spilled over into humans

The U.S. Department of Agriculture Animal and Plant Health Inspection Service awarded Cyanvac LLC a $1,999,997 cooperative agreement on February 2, 2026, under the Plant and Animal Disease, Pest Control, and Animal Care program (CFDA 10.025) to develop and evaluate a parainfluenza virus 5 (PIV5)-vectored vaccine protecting poultry from highly pathogenic avian influenza (HPAI) clade 2.3.4.4b H5N1.

Cyanvac will evaluate PIV5-vectored H5N1 vaccines expressing hemagglutinin and neuraminidase in one or two vector configurations for genetic stability and immunogenicity at varying dose levels, using mass vaccination routes including in ovo and spray administration. The work encompasses vaccine efficacy testing in naive chickens and chickens with maternal antibodies, with H5N1 challenge studies conducted in an ABSL3 facility. Immunogenicity and protective efficacy will also be assessed in turkeys. The selected H5N1 vaccine composition will undergo biodistribution and transmission evaluation.

Performance occurs in Athens, Georgia, with work running through September 30, 2028. Cyanvac, a minority-owned sole proprietorship based in Athens, operates exclusively as a federal grant recipient focused on viral vaccine development using the PIV5 platform for respiratory and zoonotic pathogens. The company holds no federal contracts or subcontract awards. This award represents its largest grant to date and complements prior NIAID funding for RSV/HMPV and HMPV intranasal vaccine development and PIV5-vectored COVID-19 vaccine formulation work.

This leads to significant economic losses to the poultry industry and increases the risk of transmission to humans. Cyanvac's pandemic influenza vaccine, using the parainfluenza virus 5 (PIV5) vector, is a novel vaccine to protect poultry from HPAI. IT can be administered using the mass vaccination techniques, is highly effective at preventing and blocking transmission of pandemic influenza in animals and is cost effective. PIV5 has been shown to be an excellent vaccine vector for respiratory pathogens. 1) PIV5 is a safe vaccine vector, used in canine kennel cough vaccines for decades, without environmental concern; 2) PIV5 grows in serum-free vero cells to high titer and has a very good genetic stability profile; 3) efficacies of PIV5- based vaccines have been demonstrated in animals and humans; 4) PIV5-based H5N1 and H7N9 influenza pandemic vaccines induce robust local IGA and serum antibodies, T cell responses, and protect against HPAI a/vietnam/1203/04 (H5N1) and a/anhui/1/2013 (H7N9) challenge in mice, guinea pigs and ferrets. In chickens in OVO vaccination of PIV5-H5 (ZL46) at 180 PFU generated an HAI titer of 512 on day 14 after hatch. 5) a PIV5-H5N1 VAC cine based on the current circulating HPAI a/bovine/texas/24-029328-01/2024 (H5N1) provides complete protection against homologous virus challenge in mice. We will evaluate PIV5-vectored H5N1 vaccines expressing HA and NA in one or two vectors for genetic stability and immunogenicity at different dose levels and through mass vaccination routes including in OVO and spray routes. Vaccine efficacy in naive chickens and chickens with maternal antibodies will be evaluated with H5N1 challenge in an ABSL3 facility. The immunogenicity and protective efficacy in turkeys will also be evaluated. The selected H5N1 vaccine composition will be evaluated for biodistribution, transmission and in vivo genetic stability. Finally, the master virus seed of the lead vaccine candidate will be produced and tested per USDA guidelines and vaccine product will be manufactured in a bioreactor at large-scale using serum-free medium and USDA-qualified vero cells for licensure application.