Protecting chickens against infectious respiratory diseases

The need

Global meat consumption and production are steadily increasing, and chicken accounts for almost half of all meat consumed. More than 50 billion chickens are produced in the world each year, including more than 600 million in Australia.

Infectious respiratory diseases pose a significant threat to commercial chicken flocks. Outbreaks can lead to reduced body weight, poor egg quality and even death of the birds, ultimately decreasing meat and egg production.

Antibiotics reduce infection rates. However, their widespread use can lead to drug-resistant bacteria that threaten human health. Inactivated vaccines can be weak and difficult to administer to large numbers of animals.

Poultry producers need more effective methods to control infectious diseases while improving animal health and welfare.

The research

The research underpinning the poultry vaccines began in the 1980s. Veterinary science researchers at the University of Melbourne isolated strains of the bacteria Mycoplasma gallisepticum and Mycoplasma synoviae and developed methods to reduce their pathogenicity. Safety studies showed that the strains no longer caused respiratory diseases in chickens and could be used effectively as live attenuated vaccines.

In 2003, APCAH researchers began working with Bioproperties to develop a live attenuated vaccine for infectious laryngotracheitis. This respiratory disease is caused by Gallid herpesvirus 1. They identified the genes involved in virulence and deleted them to create a genetically modified strain of the virus that could elicit immunity.

Technology development history

Bioproperties and University of Melbourne veterinary science researchers developed vaccine strains and conducted animal trials to assess their efficacy in laying hens and breeding stock.

Vaxsafe MG (against M. gallisepticum) was released in Australia in 1990, and Vaxsafe MS (against M. synoviae) was released in 1995. The intellectual property remains with the University and is licensed to Bioproperties in return for a royalty.

In 2003, Bioproperties started work with APCAH researchers Professor Glenn Browning and Associate Professor Joanne Devlin to develop Vaxsafe ILT, a poultry vaccine to combat infectious laryngotracheitis.

An Australian Research Council Linkage Project led to an attenuated strain of the pathogenic virus. After development of the product, in 2017 Bioproperties was authorised to conduct regulatory field trials of Vaxsafe ILT in Australia.

For each vaccine, Bioproperties is responsible for vaccine registration, production, distribution and marketing. The company successfully met strict international requirements for importing live vaccines. This enabled Bioproperties to penetrate markets not served by some of its competitors. Vaxsafe products are now available in most major markets worldwide.

Bioproperties continues to collaborate with APCAH researchers. The two groups have developed a vaccine against Mycoplasma hyopneumoniae, which causes a highly contagious and chronic disease in pigs (Vaxsafe MHP).

Their work also led to the development of Vaxsafe MG304-T, a variation of Vaxsafe-MG for use in turkeys.