Faced with the emerging disease threat posed by avian metapneumovirus (aMPV), the US Department of Agriculture (USDA) is allowing the importation of three vaccines from Boehringer Ingelheim: the live virus products NEMOVAC™ for use in chickens and AVIFFA RTI for use in turkeys and chickens, as well as the TUR-3 inactivated vaccine for primary vaccination of both turkey and chicken flocks against aMPV subtype B.
Rick Phillips, MSc, DVM, MAM, DACPVA, Head of Global Strategic Marketing Poultry for Boehringer Ingelheim, explains the context for this move and what the company is doing to support the poultry industry.
What’s the background on the current aMPV outbreak in the United States?
RP: We haven’t had this situation for a while. Types A and B of the virus are newly introduced to the US. The outbreak started in 2023 and has progressed from there. Subtype A started on the West Coast and subtype B started on the East Coast, and they converged by 2024 and into 2025. Now we’re dealing with both subtypes across multiple regions, coast to coast, and commercial layers, broilers and turkeys are all affected.
How exactly is the outbreak affecting birds?
RP: The virus causes an insidious upper respiratory disease. In broilers and breeders, mortality is generally low, but it sets up the animal for secondary bacterial infections. The environment, time of year and other management challenges can complicate it, making it difficult to manage overall bird health.
Most of the impact is morbidity, with loss of production and reduced growth rates, especially in broilers. It can affect egg production and quality in breeders. But in some areas, like turkeys, secondary infections can push mortality as high as 60%.
Can you paint a picture of the problems that producers face in managing disease caused by the virus?
RP: A key problem is the lack of a US-licensed vaccine. While aMPV has been a significant problem in other parts of the world, prompting the development of live and inactivated vaccines, the US market hasn’t needed them until now.
Another problem is that the virus’s reservoir is migratory waterfowl, similar to avian influenza. We don’t really have a lot of epidemiology to understand why it came in and why it spread like it did. But once it gets in and gets established, it essentially becomes endemic.
Lastly, it’s highly infectious, so it’s hard to control through biosecurity. That means that preventative options such as vaccines are even more valuable.
What has your company learned from its experiences with the vaccine outside the US?
RP: Our vaccines have been on the market globally for more than 30 years, so we have extensive experience with this disease and with vaccination, and a lot of data, especially from endemic areas. It was a great advantage that when the opportunity arose to bring the vaccine to the US, we came with a lot of knowledge on how to apply it and what it could do for this outbreak.
How was the experience of working closely with the poultry industry and USDA?
RP: The industry has really shown what it can get done when everyone works together. The USDA was wonderful to work with, and with the industry’s collective efforts to secure new options, they brought an immediate solution to the urgent problem.
Once the import license was granted for the vaccine, the main thing was working closely with the broiler, layer and turkey industries on how best to apply it and what to expect, along with getting a keen understanding of their current vaccination programs with respect to other diseases. Because you have to know if you can mix it with other products, and whether you might see a different reaction if you do.
We are applying our global knowledge to support effective integration and monitoring to assess vaccine success.
What has been the industry’s reaction to having these new tools available?
RP: They’ve been very excited, as well as a little shocked, as this is the first time that the USDA has permitted a live vaccine from another country into the US. It’s a significant and good precedent, because this is a known disease that we’ve been using vaccines against for 30 years. In a way, it’s an easy call, but regulations are regulations. It took a comprehensive approach from all three industries to articulate how bad the disease was and what the solutions needed to be. We didn’t have 3 or 4 years to wait for a domestically licensed product.
What would be your advice to producers that might be interested in introducing the vaccine into their existing programs?
RP: The best thing is to contact their key account manager and have a discussion. After that, our veterinary professionals will assess each situation. Every case is unique because it’s dependent on the immune status, especially the cell-mediated immune system.
There are other diseases that can suppress the immune system and make aMPV worse. That’s why we do a full assessment of the immune status of the birds and the environment, to give a comprehensive approach to solving the problem. We don’t believe this is just a ‘one disease, one solution’ approach.
Aside from the vaccine import approval, what else has Boehringer Ingelheim been doing to provide support to the industry during this outbreak?
RP: One of our key initiatives was to really get the industry focusing on the immune health status of the birds. Right now, the industry is suffering from different diseases that we haven’t seen in a while and were once considered secondary. It seems to be an indication that we’ve got transient immunosuppression, or a general weakening of the immune system.
If we can effectively boost the immune system, we can possibly solve many disease issues instead of taking the ‘one disease, one solution’ approach. We’re working on a holistic approach to that and have been very successful in solving some of the other diseases without having to vaccinate. In the case of aMPV, we believe vaccination is necessary, but a strong immune system can significantly reduce disease severity.
Do you have any insight into what the longer-term picture looks like for managing aMPV in the States?
RP: The disease is probably here to stay, so it’s not like we’re going to vaccinate and eradicate. We’re looking at control and mitigation.
In some form, vaccination will probably continue. Right now, we’re operating under temporary emergency use of this vaccine, but long-term, the industry will need a fully licensed US product. We’re working with the government to see if we can fast-track a licensed product for domestic production. Boehringer Ingelheim has the facilities and the capabilities, and we are willing to spend the time and energy to make it happen.
