IPPE: E. coli pressure is rising – why vaccine application is key

29 June 2026

4 minute read

By: Sarah Mikesell

North America

Dr. Fernando Ruiz Jimenez, a technical services veterinarian at Zoetis, spoke to The Poultry Site’s Sarah Mikesell at IPPE 2026 in Atlanta, Georgia, USA, about layer vaccination. 

Layers are considered high value birds in poultry production. From a health management perspective, why does that make disease prevention, particularly vaccination quality so critical? 

Layers don’t have a turnaround of 6-8 weeks like broilers. In layers, you don't start seeing your investment give results until at least 20 weeks, when they start producing eggs. You have to be careful during the first phase with pullets, when you want them to be as healthy as possible while meeting their target weights and maintaining uniformity, so you can get the best bang for your buck and that involves adequate vaccination. 

It’s your chance to protect them against any diseases that they may face in the field. You need to be very careful because, on top of what you paid for the pullets, you're paying for vaccines. Handling the vaccination well can help provide the return on the vaccine investment you’re making to help protect the birds. 

E. coli continues to be a challenge in layer systems especially for floor raised birds. What makes these birds more vulnerable and how can E. coli infections complicate other health challenges like infectious bronchitis? 

Unfortunately, we've been seeing E. coli as the top issue across the board in conventional and cage-free systems, but we do tend to see it more often in cage-free. That likely has to do with the birds being on the floor and having access to different parts of the house. It may also be more dusty. 

E. coli is a bacteria that is everywhere. Birds being able to have access to different areas that they don’t have in conventional systems elevates the possibility of them facing a higher load of E. coli. On top of that, with other potential risks like bronchitis or other disease pressure, or a little higher stress when they start laying and/or there is higher ammonia concentration, E. coli can take advantage of those immune system stressors and start causing issues. 

Producers often assume protection once birds are vaccinated. Why is validating vaccine application quality such an important step in confirming that protection? 

When investing in vaccines, producers should do their best to get the most value for their money. With E. coli, the vaccine is a little different. With viral vaccines, the birds get vaccinated, then they shed that vaccine virus, so the virus will be in the house for a little while. 

When an E. coli vaccine is applied, they shed the E. coli, but the E. coli won't survive in the environment for long. Birds that were not vaccinated initially will not be able to see the E. coli vaccine later from the shedders. If you miss a bird, it'll stay susceptible for the rest of its life. Because of this, you really need to make sure that you're getting a full vaccine dose on each bird to try to verify that most of the flock will be protected.

There are different ways of doing that. You can just watch the crews – that's the easiest way to do it. Make sure that they're mixing and handling the vaccine correctly and application is effective. Just stay on top of the application process and try to make sure that they're doing the best they can. 

Is monitoring an effective method to reduce mistakes with vaccination? 

Yes, sometimes mistakes happen because the crews do vaccinations all the time. You just assume they're doing it right. With some vaccines, you could get away with it. But with the prevalence and risk of E. coli, as well as the nature of the vaccine, you must make sure the vaccine is properly applied. 

How does a pullet vaccination evaluation (PVE) help producers assess whether vaccination was successful from an immune response standpoint? 

Most people will have their internal audits. People go in and check on the crews, and it becomes a routine. The auditing process can be repetitive, so it's easy to start overlooking some things. It can be helpful to bring a third set of eyes in to bring a new perspective and catch some mistakes or areas of improvement you may have missed. 

That's our role when we come in. We do a comprehensive evaluation, not only of the vaccination itself, but all the process from storage and handling and how they mix the vaccine. We try to hit all the critical points to make sure that everything is in line with what we recommend and help ensure that the vaccine can be effective.

Vaccine crew training is paired with the PVE service. How does crew training directly impact vaccine consistency and overall protection against E. coli? 

Crew training is another component of PVEs. Sometimes producers assume the crew is a separate entity. They're people, and they really want to improve and know what they are doing wrong, but if you don't take them into consideration and include them in discussions, that message can be lost. 

You can be talking to management, but if you don't relay your message to the people that will actually make those changes, that can be a barrier to having the changes understood and applied.

It’s important to monitor the crew and relay your message to them with recommended changes, why you’re making those recommendations and the potential results from those efforts. That's an important component of a vaccine evaluation – get the crew involved and help them improve.