The United States’ Proposed Vaccination Plan for Avian Influenza

 

Professor Dr. Salah Mahdi Hassan, Poultry Health and Production Consultant

 

The United States’ Proposed Vaccination Plan for the Highly Pathogenic H5N1 Avian Influenza for the Table Egg Poultry Industry:

Comparison with the Iraqi Vaccination Plan

 

It has become clear that the H5N1 influenza virus may become endemic in animals in Europe and the Americas, a significant turning point for highly pathogenic H5N1 influenza viruses, necessitating the adoption of new control strategies, including vaccination.

Licensed influenza vaccines for poultry limit the effects of the disease, but they do not prevent infection, and their success has been mixed. China’s large-scale national poultry vaccination program has been credited with controlling H5 and H7 viruses and limiting zoonotic disease. However, vaccination campaigns have been less successful in controlling H6N2 in South Africa or H5N2 in Mexico, which recently reported zoonotic cases.

A major concern regarding vaccine use is that vaccines could make it more difficult to control avian influenza by promoting the latent spread of the virus and/or accelerating antigen evolution in poultry. Major poultry exporters in Europe, Brazil, and the United States are reluctant to use influenza vaccines in poultry or cattle because vaccinated animal products are subject to international trade restrictions. For example, when France became the first EU country to vaccinate domestic ducks against H5N1 in 2023, the United States banned the import of duck products from France and all of its trading partners, citing the perceived risk that vaccinated animal products could introduce subclinical H5N1 infection into the country.

Given that H5N1 has become endemic in wild birds worldwide, pressure is mounting to reconsider trade restrictions designed for a different phase. The World Organization for Animal Health (WOAH) issued a statement in 2023 stating that influenza vaccination of poultry “should not be a barrier to safe trade.” However, countries need to conduct intensive surveillance of virus populations in poultry and identify the dominant virus strain for use as a vaccine, as in humans. There is hope that one day, the National Institutes of Health will succeed in its ambitious plan to develop new influenza vaccine platforms for humans that provide broad protection against all genetically diverse IAV strains, providing more platforms for effective avian influenza vaccines in animals. However, these vaccines are still in the early stages of research.

The U.S. laying hens industry has suffered significant losses due to outbreaks of highly pathogenic avian influenza (H5N1 clade 2.3.4.4b), which has caused significant mortality and subsequent culling of laying hens. This has led to a severe shortage of table eggs in U.S. commercial markets, which has driven up egg prices. For years, U.S. veterinary authorities have responded by not vaccinating, but rather by implementing biosecurity measures, culling infected flocks, and allowing a rest period for infested fields to allow for the repopulation of new flocks. Naturally, fear has plagued poultry farmers and large-scale enterprises.

Therefore, professional associations such as the United Egg Producers and the American Egg Board, which represent table egg producers in the United States, have approached the Department of Agriculture directly or through the U.S. Congress to find effective solutions and the possibility of using a vaccine to reduce the risk of the disease. It is important to note that the virus has taken a “dangerous” turn by infecting cattle and a number of other mammals in both land and sea, in addition to human infections among a number of workers in infected poultry projects.

On February 26, 2025, the U.S. Department of Agriculture announced a comprehensive $1 billion strategy to reduce Highly Pathogenic Avian Influenza (HPAI), protect the U.S. poultry industry, and lower egg prices, as well as funding to actually compensate farmers for discarded and culled flocks.

As the ministry explained, the five-pronged strategy includes an additional $500 million for biosecurity measures, $400 million for financial compensation for affected poultry farmers, $100 million for vaccine research, measures to reduce regulatory burdens, and exploring temporary import options.

The USDA’s Five-Step Approach to Addressing H5N1 Highly Pathogenic Avian Influenza:

First: Invest in gold-standard biosecurity measures for all U.S. poultry producers.

– The USDA will expand its highly successful wildlife biosecurity services to include producers nationwide, starting with egg-laying poultry farms, to protect them from highly pathogenic avian influenza, which has an 83% chance of transmission from wild birds. These additional security measures have proven successful in reducing influenza cases, with approximately 150 projects implementing these measures experiencing only one outbreak.

– Expand biosecurity audits of production farms, which are free for all projects affected by highly pathogenic avian influenza. The extent of production losses at farms affected by HPAI must also be determined to qualify for compensation for future outbreaks. Biosecurity audits of surrounding and unaffected fields will also be encouraged.

– The USDA is identifying 20 trained epidemiologists as part of its increased biosecurity audits and wildlife biosecurity assessments to provide timely and practical advice to producers on how to reduce the risk of HPAI in their operations. These experts will help improve current biosecurity measures to focus on protecting against both wild bird spread and horizontal spread.

– The USDA will cover up to 75% of the costs of biosecurity measures identified through the assessments and audits, with a total available investment of up to $500 million.

Second: Increase compensation to help business owners and accelerate the reintroduction of new chicken feeds.

– The Animal and Plant Health Services (APHIS) continues to compensate producers who must cull their flocks to control the spread of highly pathogenic avian influenza.

– Explore new programs to help farmers accelerate the reintroduction of new feeds to their flocks, including ways to streamline the official approval process to speed up recovery.

– Provide up to $400 million to support these costs during the remainder of the fiscal year.

Third: Removing unnecessary regulatory burdens on the poultry and egg industry to promote innovation and lower prices for consumers.

– The USDA is working with the U.S. Food and Drug Administration to examine strategies to safely expand product offerings in the commercial egg market.

– The USDA will work to reduce burdens on individual egg producers and consumers who consume domestic eggs.

– The USDA will work with producers and scientists to develop innovative strategies to reduce the number of birds discarded or killed during outbreaks of highly pathogenic avian influenza.

– The USDA will educate consumers and Congress on the need to address geographic disparities in egg prices, such as in California, where recent regulatory burdens, combined with avian influenza, have caused egg prices to rise 60% compared to other regions of the country.

Fourth: Identifying pathways to vaccines, therapeutics, and other strategies to protect laying hens and reduce population declines.

– USDA will place significant emphasis on a targeted and deliberate strategy for potential next-generation vaccines, therapeutics, and other innovative solutions to reduce laying hens’ population declines, along with increased biosecurity surveillance and other innovative solutions targeting laying hens in and around outbreak areas. Up to $100 million in investment will be made available for innovation in this area.

– It is important for USDA to work with trading partners to minimize potential impacts on export markets if the vaccine is used. Additionally, USDA will work closely with the U.S. Department of Health and Human Services to ensure the public health and safety of any such approaches, including considerations related to the balance between public health and infectious disease strategies.

– USDA will seek public input on proposed solutions and engage state governors, state departments of agriculture, state veterinarians, and poultry and dairy farmers in vaccine and therapeutics strategy, logistics, and surveillance. The USDA will immediately begin bi-monthly discussions on this matter and will update the public on its progress every two weeks until further notice.

Fifth: Study temporary import and export options to reduce costs for consumers and evaluate international best practices.

– The USDA will explore the option of temporarily increasing egg imports and reducing exports, if necessary, to meet domestic market demand, subject to safety reviews.

– The USDA will evaluate international best practices in egg production and safety to identify opportunities to increase domestic supply.

Pursuant to Section 4 of the USDA’s Highly Pathogenic Avian Influenza (H5N1 clade 2.3.4.4b) Containment Plan, the American Egg Federation and the U.S. Egg Board convened a committee of American researchers, including Dr. John Clifford, Craig Rowles, Travis Schaal, and David Swayne, to develop a practical and accurate plan for the use of vaccines against high-pathogenic avian influenza. The committee published a proposed vaccination plan on April 1, 2025, to address the ongoing highly pathogenic avian influenza (HPAI) outbreak affecting the U.S. table egg industry.

The proposed plan emphasized the following key points and practical conclusions:

1. The intensive biosecurity measures implemented following the outbreak of highly pathogenic avian influenza in 2014 and 2015, along with the accompanying mass culling and culling, proved insufficient to reduce these outbreaks. It should be noted that since 2022, more than 131 million laying hens have been culled, causing a significant decline in egg production.
2. The proposed plan calls for the design of a vaccination strategy and considers it a complementary process to current biosecurity measures. Vaccination aims to enhance immunity against the highly pathogenic H5N1 avian influenza virus and reduce virus shedding by exposed chickens, which in turn reduces environmental contamination. This is essential and necessary to prevent viral mutations with serious consequences for human health. 3. Vaccinating newly hatched chicks in the hatchery is considered more effective in immunological control than vaccinating chickens in production. This poses field challenges, especially in projects or fields that follow land-based breeding and production systems. Additionally, currently available vaccines require a single injection for each bird.
3. The report recommends a regional vaccination strategy based on identifying “vaccination zones.” This approach focuses on egg-laying chickens and turkeys and seeks to maintain international trade by allowing vaccinated flocks to be presented to trading partners, thus mitigating trade barriers.
4. The proposed program includes the use of vaccines licensed by the United States Department of Agriculture (USDA), starting with the first vaccination of chicks at one day of age, followed by booster doses during the growing phase, with the goal of establishing high immunity at the flock level within 12 to 18 months, meaning full coverage of the flock’s productive period.
5. Continuous monitoring of vaccine effectiveness is considered “essential.” Monitoring is based on a procedure Serological tests for specific antibodies, as well as screening for active viruses, are used to detect infection in vaccinated flocks. 7. Vaccination in poultry has been shown to reduce the risk of human infection associated with highly pathogenic avian influenza by reducing influenza virus shedding and virus spread among chickens, thereby reducing environmental contamination. This ultimately reduces or eliminates the need for poultry depopulation and disposal.
6. Continuous monitoring of vaccine efficacy is considered “essential.” Monitoring involves conducting serological tests for specific antibodies, as well as screening for active viruses to detect infection in vaccinated herds.
7.  It has been proven that the use of vaccination in poultry reduces the risk of human infection associated with highly pathogenic avian influenza, by reducing the shedding of the influenza virus and reducing the spread of the virus among chickens, thus reducing environmental pollution, which ultimately leads to reducing or eliminating the need for poultry depopulation and disposal.

In conclusion, implementing a vaccination plan is essential to better manage and control outbreaks of highly pathogenic avian influenza in laying hens. Vaccination aims to protect poultry and human health by reducing infection rates and environmental transmission of the virus. This strategy reflects lessons learned from previous outbreaks and simultaneously represents a proactive and preventive enhancement of biosecurity in poultry. This closely mirrors the strategy we have proposed for implementation. For all the above, I would like to present this to all those interested in the Iraqi poultry industry, from both sides—breeders and Iraqi veterinary authorities, represented by the esteemed Veterinary Department—for comparison with the Iraqi plan to combat the highly pathogenic H5N1 avian influenza. This can be summarized simply as follows:

1- The decision regarding the type of vaccine officially approved was only the killed vaccine for the H5N1 subtype, and, as I recall, a specific company was tasked with preparing the vaccine.

2- Today, the Iraqi market for H5N1 avian influenza vaccines includes numerous types of vaccines from various companies. I do not know how the government license was granted for them, nor was an official decision issued to add these vaccines to the official order in 2021. Of course, this is considered biological chaos, the seriousness of which no one can determine.

3- Another, very serious matter: Is there a government veterinary order to use a dual-strand vaccine for H5 and H9 avian influenza? And how was the government license granted for such extremely dangerous vaccines, according to what scientific research has stated and published. My most important question is directed to the Epidemiology Division: What is your assessment of the use of such vaccines?

4- Didn’t the official approval for the use of the H5N1 vaccine include the need to monitor vaccinated chicks through periodic serological tests and viral swabs from the complex, to detect neutralizing antibodies and field viruses to ensure the immunological efficacy of the vaccine used?

• I am very confident that the Veterinary Department is following the directives of the World Organization for Animal Health. Don’t you know that the organization’s primary directive for countries using the vaccine is to have an exit route? Therefore, has a field study been conducted to determine the efficacy of the vaccine used?

Finally: as a religious advice and as a poultry disease specialist, and as I claim to be familiar with a large amount of information about bird flu, both global and regional, I call upon the esteemed Veterinary Department to prepare a complete and comprehensive study on bird flu vaccines in Iraq and their effectiveness, wishing them success.