We Should Vaccinate Egg-Laying Hens Against H5N1

But maybe allow the chicken meat industry to decide for itself

Matthew Yglesias

recently argued that the US should be vaccinating chickens against H5N1. According to Matt, the risk of H5N1 causing a human pandemic is relatively low, but it’s non-zero, and vaccinating chickens could help reduce that risk. It would also help stabilize egg prices, which are at record levels, and resolve some of the important animal welfare issues around H5N1.

I largely agree with Matt’s analysis, but I think there could be a more nuanced policy response that may prove more effective: vaccinating chickens in the egg industry, but not the meat industry. This targeted approach could boost abundance in our food system while solving a critical challenge in animal agriculture.

As Matt points out, the most commonly cited reason why we don’t currently vaccinate chickens is because of international trade. The US is a major chicken meat exporter, and many of our trade agreements don’t allow for bird flu vaccination. The concern is that vaccines might suppress symptoms but not eliminate the virus entirely, so if you import from a country that vaccinates, you risk accidentally bringing in the virus into your country.

Ironically, if importing countries were also vaccinating their birds, they might worry less about this since their flocks would already be protected However, there’s a coordination problem where no one wants their trade partners to vaccinate, and no one’s trade partners want them to vaccinate, so no one vaccinates. But arguably we’d all be better off if we all just vaccinated.

Unfortunately, coordination problems can be difficult to solve, especially when they involve so many countries each of which must navigate its own complex web of domestic interests. This means that there’s a high bar for any country that cares about exports to start vaccinating. Matt says “the industry doesn’t see the economic benefits of vaccination as worthwhile, especially given the export complications.”

However, it’s important to understand that the economic cost and benefits of vaccination are different depending on what part of “the industry” you’re talking about. Poultry is many things: it can refer to either the egg industry (where chickens are called “layers”), the chicken meat industry (where chickens are called “broilers”), the turkey industry, or any of the other industries that produce animal products that come from birds.

And there’s a reason that it’s eggs prices that have been making headlines, not chicken meat prices: H5N1 primarily affects the egg industry. Of the birds affected by to H5N1, 73% were layers, 14% were turkeys, and the other 13% were broilers or other kinds of birds.

The disproportionate impact of H5N1 on the egg industry is even more pronounced given that:

1. There are 300-400M layers in the US at any given time, while we produce over 9 billion broilers each year, over 1 billion of which are alive at any given time. Measured in terms of chicken-days, the broiler industry is over three times bigger, but bears less than 13% percent of the burden of H5N1.

2. An individual laying hen is 3x more economically valuable than an individual broiler chicken, meaning that when a layer flock needs to be depopulated, the economic toll is substantially higher than when a broiler flock is depopulated.

One potential reason H5N1 is hitting layers so much harder than broilers is that layers tend to live around 2 years, while broilers are usually 4-6 weeks old when they’re slaughtered, giving layers more time to be exposed to the disease. Another potential reason is that most of the broiler industry is concentrated away from the Pacific and Central flyways, where HPAI is most prevalent in migratory birds.

On the other side of the equation, exports are a much bigger issue for the broiler industry. We export 14-15% of our chicken meat but only 3-4% of our egg products, so import bans from our trade partner would disproportionately affect the chicken meat industry. And as Slow Boring commenter

Phillip R

pointed out:

While exports only account for 15-20% of poultry production, they play an outsized role in the value of the bird, as the 15-20% is not distributed evenly across all bird parts.

Americans love to eat chicken wings and chicken breasts, but you can't grow a chicken that's only wings and breasts. Other countries prefer different parts of the bird including legs, dark meat, and "paws" (chicken feet). By exporting those parts of the bird, we limit food waste and create a market for chicken parts that otherwise of little value. Without these export markets bringing value to all parts of the bird, the overall value of producing an individual bird will plummet - and make the parts Americans love (wings and breasts) significantly more expensive as production declines.

Therefore, the costs of poultry vaccination against H5N1 will primarily be paid by the chicken meat industry, but the benefits will primarily accrue to the egg industry. I’m not privy to whether this misalignment of incentives is affecting conversations about vaccination in Washington DC, but it seems easy to imagine a scenario in which different parts of the poultry industry are not on the same page about what to do. There is some evidence this may in fact be the case: according to Reuters, late last year “The nation's leading egg, turkey and dairy groups argued in an August letter to Agriculture Secretary Tom Vilsack that the economic toll of the outbreak justifies deploying a vaccine.” Notably absent from this coalition is the chicken meat industry. Indeed, The National Chicken Council, which is a trade group representing the chicken meat industry publicly opposed vaccination, although that was back in 2023.

This raises the question: why can’t different parts of the poultry industry make different decisions? The supply chains for layers and broilers are completely separate. They use different breeds of birds, are raised in completely distinct facilities, and almost no companies have substantial operations in both. Other than working with the same species of bird, they’re essentially two separate industries.

In theory, it seems like we should be able to vaccinate layers in order to stabilize egg prices, improve animal welfare, and reduce the risk of a pandemic, all without affecting broiler exports. Then, the chicken meat industry should be able to decide for itself whether the economic costs of reduced exports outweigh the benefits of vaccination. But in practice, the USDA seems to be making a determination on behalf of the entire poultry sector, so the fates of layers and broilers are intertwined.

I’m no expert in international trade, so I don’t know how our trade partners would react to such a proposal. Historically, it does seem like there’s a lot of risk aversion around accidentally bringing a livestock disease through imports. And, we haven’t always been that lenient ourselves as an importer. For example, when France started vaccinating ducks against H5N1, the US banned all poultry imports from France, including chickens, and we also banned duck imports from most of Europe.

So maybe our trade partners still wouldn’t allow us to export our broilers if we vaccinated our layers. And there are certainly major logistical issues with rolling out a vaccine for layers, especially if was still disallowed for broilers. But it seems to me that in the sanest possible world, where coordination was not an issue and reason always prevailed, we would be using all of the tools and technologies at our disposal to fight this horrible virus, which means vaccinating the egg industry. We’d do it for our public health, for the health and welfare of the birds, and because the price of eggs is too damn high.