Animal health companies are advancing vaccines to improve the effectiveness of protection against avian influenza, with recent developments marking a third generation of technology since the initial vaccines of the late 1700s. Dr. John El-Attrache, a global science director at Ceva Animal Health, shared insights on this evolution at the recent Egg Industry Issues Forum, where he outlined the progression of vaccine technology and its impact on disease control in poultry.
The earliest vaccines relied on weakened or killed versions of pathogens to initiate immune responses, though the avian influenza vaccines from that era were often poorly matched to the virus, providing limited and narrow immunity. This initial technology was later enhanced with a second generation of vaccines, about 15 years ago, which uses viral vectors to create a more comprehensive immune response. HVT vaccines, a notable type in this generation, employ a turkey herpes virus as a vector and remain highly effective even against new virus strains by activating two types of immunity.
The latest generation, nucleic acid vaccines, includes Ceva’s avian influenza vaccine currently used in France for ducks and shares similarities with COVID-19 vaccines from Pfizer and Moderna. Among these, self-amplifying RNA vaccines are proving especially promising, offering the advantage of lower dosages, cost-effectiveness, rapid development, and protection against multiple virus strains. This type of vaccine can be manufactured within a brief timeframe, approximately five weeks, and offers adaptability to different variants.
Meanwhile, Boehringer Ingelheim has developed a vaccine targeting avian influenza along with HVT and infectious bursal disease through an H5 antigen that recognizes shared components of these viruses. This approach aims to provide extensive protection, covering strains that have not yet emerged. Though avian influenza vaccines are not currently used in U.S. poultry, this triple-threat vaccine is registered in the United States and is used in other countries, positioning it as a versatile solution to various viral threats in poultry.
As avian influenza itself has evolved, a recent H5 variant discovered in China has caused waves of infection over the past decade, spreading across wild birds, domestic poultry, and even mammals. Despite the increasing threat, the U.S. remains cautious about avian influenza vaccination for commercial birds due to potential trade restrictions, as vaccinated and infected birds both display antibodies. However, newer vaccines address this issue by creating antibodies with specific markers that differentiate them from those arising from infection. Last December, the World Organisation for Animal Health indicated that well-managed vaccination campaigns should not hinder trade.
With avian influenza becoming less predictable and the number of affected species rising, some experts, including Dr. Taoufik Rawi of Boehringer Ingelheim, advocate for revisiting avian influenza prevention strategies. Rawi outlined the global uses of avian influenza vaccines, from reducing clinical symptoms and maintaining production levels to fully eradicating the virus and mitigating human health risks. Vaccines play a central role in France’s eradication efforts, where Boehringer Ingelheim and Ceva provide vaccinations for ducks, part of a comprehensive approach to control the virus. In addition to reducing virus spread through decreased replication and shedding, these vaccines can mitigate environmental impacts and help sustain the livelihoods of poultry farmers. As poultry remains a critical protein source worldwide, maintaining its production is essential, and vaccines offer a promising route to achieving a balanced and effective response to avian influenza.
