LSU Vet Med researcher awarded nearly $2 million grant to develop a bird flu vaccine for poultry

A research team led by Mariano Carossino, DVM, Ph.D., DACVM, DACVP, associate professor of veterinary pathology at the LSU School of Veterinary Medicine, has been awarded nearly $2 million by the U.S. Department of Agriculture (USDA) to develop an innovative vaccine to protect poultry against highly pathogenic avian influenza (HPAI) H5N1, commonly known as bird flu.

The funding, awarded through the USDA Animal and Plant Health Inspection Service (APHIS) Highly Pathogenic Avian Influenza Poultry Innovation Grand Challenge program, will support research aimed at developing a vaccine that provides earlier, stronger, and more practical protection against the virus, which has devastated poultry flocks across the United States.

Since the current outbreak began in 2022, HPAI H5N1 has resulted in the loss of more than 168 million commercial and backyard poultry birds nationwide, disrupting food supplies, contributing to egg shortages, and increasing costs for consumers. The virus has also spread to other animal species, including dairy cattle, where it was first detected in the United States in 2024.

"Highly pathogenic avian influenza continues to pose a serious threat to animal health, the poultry industry, and our nation's food supply," Dr. Carossino said. "Our goal is to develop a vaccine that provides effective protection against the virus while also being practical for poultry producers to administer on a large scale."

Developing a new approach to vaccination

The LSU Vet Med project, titled "Nanobody-directed, M-cell-targeted mucosal vaccine against HPAI H5N1 clade 2.3.4.4b in poultry," brings together expertise in vaccinology, virology, immunology, and pathology to develop a new approach to protecting poultry.

Unlike conventional vaccines, the LSU-developed approach uses nanobodies, small antibody-derived molecules, to direct vaccine components to specialized immune cells in the intestinal tract. This approach is designed to stimulate mucosal immunity, strengthening the body's defenses at sites where infection often begins.

By targeting these entry points, researchers hope to prevent infection while also generating a broader immune response throughout the body.

The research team is incorporating advanced vaccine technologies, including self-amplifying RNA and replication-deficient viral vectors. These technologies are being designed to allow vaccination either in ovo, before chicks hatch, or through drinking water.

Both methods could make vaccination more efficient and practical for commercial poultry operations, where large numbers of birds must be protected.

Protecting poultry and the U.S. food supply

Current strategies for controlling HPAI rely heavily on biosecurity measures, disease surveillance, and rapid outbreak responses, which often require the depopulation of infected flocks to prevent further spread.

Although several avian influenza vaccines have received conditional licenses from the USDA, no HPAI vaccine has been authorized for use at this time, except on a case-by-case basis in certain endangered or zoo species.

The LSU Vet Med research aims to address several challenges associated with existing vaccine approaches, including the need for stronger protection, practical administration methods, and the ability to distinguish vaccinated birds from naturally infected birds.

If successful, the vaccine could:

• Provide earlier and stronger protection against HPAI H5N1.
• Allow efficient vaccination of large poultry populations through drinking water or before chicks hatch.
• Support disease surveillance by helping distinguish vaccinated birds from infected birds.
• Reduce economic losses for poultry producers and help protect the nation's food supply.

Because HPAI H5N1 is widespread among migratory wild birds, which can carry and spread the virus across North America, eliminating the disease entirely is unlikely. Developing effective vaccination strategies could provide an important additional tool for long-term disease control.

The USDA-funded project represents LSU Vet Med's ongoing commitment to advancing research that protects animal health, supports agricultural industries, and addresses emerging infectious disease threats.

Acknowledgments: This material was made possible, in part, by a Cooperative Agreement from the United States Department of Agriculture's Animal and Plant Health Inspection Service (APHIS). It may not necessarily express APHIS' views.

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