The highly pathogenic avian influenza (HPAI) epidemic has taken a huge toll around the world, but there appears to be hope.The USDA has confirmed that the department’s Agricultural Research Service has completed preliminary testing Five HPAI vaccine candidates. Specifically, the scientists evaluated a highly pathogenic avian influenza vaccine developed in-house at the USDA and four commercial highly pathogenic avian influenza vaccines.
These studies, which have not yet been made public, show that “All five vaccines significantly reduced oral and cloacal virus shedding and provided close to 100% clinical protection in chickens.”, they explained.
Agricultural Research Service scientists also continue to work on vaccine testing. They will evaluate the vaccine’s effectiveness in turkeys and the duration of immunity in several species of bird species. They have also developed and will continue to optimize and validate diagnostic tests required for vaccination. “These are long-term studies. We estimate Study results on turkey efficacy and duration of immunity will be published in summer 2024“.
French vaccine
It is worth remembering that in October this year, the French government approved a highly pathogenic avian influenza vaccine for farmed ducks, becoming the first European country to do so. While the effectiveness of France’s vaccination program has yet to be determined, Drs. David SwainThe head of the USDA Southeast Poultry Research Laboratory in Athens hopes the U.S. will soon follow suit and make approved poultry vaccines available to producers.
However, they explain that there are Possible disadvantages. France’s use of the vaccine led to a ban on the export of poultry, duck meat and foie gras. “If countries vaccinate against highly pathogenic avian influenza, international agreement requires that vaccinated flocks be separated from those exposed to highly pathogenic avian influenza viruses. If there is no capacity to make and receive This distinction, vaccination of U.S. poultry against highly pathogenic avian influenza could have large and lasting impacts on poultry genetics and product trade. “
On the other hand, they explain that current vaccines may be relatively effective at preventing disease but less effective at eliminating transmission of the virus, which is required by the World Organization for Animal Health. “More research is needed to identify vaccine candidates and strategies that meet international trade agreements.”, they emphasized.
multiple methods
The International Alliance for Biological Standardization recommends establishing an advisory committee with broad stakeholder participation; developing pilot vaccination programs in multiple countries to develop monitoring and surveillance plans; isolation sharing; examining reductions in infections in vaccinated animals; supporting translational research , to accelerate vaccine commercialization and the development of risk assessment templates.
The U.S. Department of Agriculture also believes Consider as many ways as possible to protect and respond to highly pathogenic avian influenza, including vaccination of vulnerable bird populations. They argue: “The decision to vaccinate is complex: from vaccine development to production planning to dissemination to birds, there are many factors that make implementing a vaccination strategy challenging and taking time to administer an effective vaccine.”
Currently, they are betting on IBiosecurity is the best defense against highly pathogenic avian influenzaand strongly recommends that all bird owners review wildlife management resources to prevent avian influenza, evaluate their biosecurity plans, and develop strategies to prevent exposure to wild birds or their feces.
Swain said, assuming a vaccine is approved, the next steps are Producer acceptance, some of whom refuse to use the vaccine because they fear it will cause real HPAI infections in vaccinated flocks. Likewise, producers fear suffering the same fate as France, as countries could outright ban imports of U.S. poultry without being able to distinguish between vaccinated and infected flocks.
“Ultimately, I hope scientific ideas and scientific data will prevail and show Vaccines are very useful in preventing any of these solid infectionsSwain explained. “In general, Threat and fear of widespread infection among vaccinated chicken flocks has no scientific basisand this concern is largely based on a misunderstanding of the vaccine effectiveness data,” he said.
“Vaccination does not replace biosecurity,” he continued, but “if you have good biosecurity and only small particles of virus are getting through, The vaccine works well at preventing infection“.