Mastering Hatchery Vaccination for Bronchitis Control

Introduction

Avian Infectious Bronchitis (IB) is a highly contagious viral disease of chickens, caused by a gamma-coronavirus.

It affects respiratory, urinary and reproductive systems, and can result in respiratory distress, reduced growth, poor feed conversion, and in layers, serious damage to the oviduct ; leading to lower egg production and degraded egg quality.

One of the most severe consequences of IB is airsacculitis, an inflammation of the air sacs in chickens. This condition leads to the accumulation of purulent or caseous material, rendering affected tissues unsuitable for human consumption. In severe cases, entire carcasses must be discarded, slowing down processing lines and increasing operational costs. With new IB variants emerging regularly, the need for a robust, adaptable, and efficient vaccination strategy is more critical than ever.

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Vaccination remains the most effective tool in the fight against infectious bronchitis. While biosecurity and hygiene practices are essential, they are not sufficient on their own to prevent outbreaks. The virus spreads rapidly through airborne transmission, contaminated equipment, and personnel, making early and comprehensive immunization a necessity.

A well-structured vaccination program helps build immunity in chicks from the earliest stages of life. Hatchery vaccination offers a strategic advantage by ensuring that day-old chicks are protected before they are exposed to environmental pathogens. This early protection is crucial in reducing the risk of infection and minimizing the spread of the virus within and between flocks.

Moreover, the economic benefits of vaccination are substantial. By preventing disease outbreaks, producers can avoid losses related to reduced growth rates, poor feed conversion, decreased egg production, and increased mortality. Vaccination also helps maintain the quality of meat and eggs, ensuring compliance with food safety standards.

Spray vaccination has become the preferred method for administering live respiratory vaccines to day-old chicks in hatcheries. This technique involves the use of specialized equipment—such as in-line or cabinet sprayers—that deliver a coarse spray of vaccine solution over the chicks. The target is the upper respiratory tract, providing localized immunity where the virus typically enters the body.

The success of spray vaccination depends on several critical factors.

First, the equipment must be properly calibrated to ensure uniform coverage. Parameters such as air pressure, nozzle spray pattern, volume delivered per nozzle, and crate coverage must be precisely adjusted. Room humidity also plays a role in ensuring that the vaccine droplets size is correct while inhaled by the chicks.

Second, the vaccination environment must be controlled to minimize stress and ensure optimal absorption. Chicks should be calm and evenly distributed in the crates during vaccination. Excessive noise, movement, or the vaccination room temperature are also key criteria.

Finally, the personnel operating the equipment must be well-trained and experienced. Even the most advanced machines cannot compensate for human error. Regular maintenance, cleaning, and calibration of the equipment are essential to ensure consistent performance and prevent contamination.

The preparation of the vaccine solution is a critical step that directly impacts the effectiveness of the vaccination process. Live-attenuated IB vaccines are typically supplied in lyophilized (freeze-dried) form and must be reconstituted with a suitable diluent—usually distilled or low-mineralized water—before use.

Water quality is a key determinant of vaccine viability. Factors such as mineral content, pH, and microbiological load can affect the stability of the vaccine virus. Chlorinated water, for example, can inactivate the virus, rendering the vaccine ineffective. Therefore, it is recommended to use distilled water or water with low mineralization and a neutral pH (between 6.5 and 7.5).

Water temperature is another important consideration. Studies have shown that high temperatures can degrade the vaccine virus, reducing its immunogenicity. The ideal temperature range for reconstitution is between 8°C and 25°C (46°F to 77°F). Once reconstituted, the vaccine should be used within one hour to maintain its potency.

The reconstitution process should follow standardized operating procedures (SOPs) provided by the vaccine manufacturer.

These procedures typically include the following steps:

Fill a sterile 20 mL syringe with 5–10 mL of distilled water using an 18G needle.
Inject the water into the vaccine vial containing the freeze-dried virus.
Mix thoroughly to dissolve the powder completely.
Withdraw the reconstituted solution with the syringe.
Transfer the solution to the vaccine tank of the hatchery sprayer.

It is essential to maintain aseptic conditions throughout the process to prevent microbial contamination. This includes using sterile equipment, wearing gloves, and working in a clean, dedicated area free from disinfectants. The infectious bronchitis virus is an enveloped virus and is particularly sensitive to disinfectants and heat. Therefore, non-metallic containers are recommended for mixing the vaccine solution.

Good Vaccination Practice (GVP) encompasses the entire vaccination process—from storage and preparation to administration. Vaccines must be stored at a constant temperature of 2°C to 8°C to preserve their immunogenicity. Any deviation from this range can compromise the vaccine’s ability to elicit a strong immune response in birds. Expired vaccines must be discarded immediately, as their efficacy cannot be guaranteed.

Regular training and supervision of hatchery staff are essential to ensure compliance with GVP. High staff turnover in hatcheries makes ongoing education and support even more important. Visual aids such as posters and video tutorials can help reinforce best practices and improve consistency.

Preventing infectious bronchitis in poultry requires a comprehensive and detail-oriented approach. While vaccination is the most effective tool, its success depends on proper planning, execution, and monitoring. Spray vaccination at the hatchery offers a powerful means of early protection, but it must be supported by meticulous vaccine preparation and adherence to Good Vaccination Practices.

Programs like Ceva’s C.H.I.C.K. initiative provide valuable support to hatcheries worldwide. By offering training, standardized procedures, and on-site monitoring, these programs help ensure that every step of the vaccination process is performed correctly. In an industry where consistency is key and the stakes are high, such support can make the difference between success and costly outbreaks.

By following best practices in vaccine storage, reconstitution, and administration, poultry producers can safeguard their flocks, protect their operations, and contribute to a healthier, more resilient food supply chain.

The fight against infectious bronchitis is far from over—but with the right tools and knowledge, it's a battle we are well-equipped to win.

© Ceva Santé Animale