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Enhancing Flock Immunity: Analyzing Vaccination Serology Field Trial Results in Poultry

Flock vaccination has been shown to play a crucial role in animal disease prevention and optimizing immunity and productivity on commercial farms worldwide. Specifically, in the poultry production industry, many operations are implementing strict vaccination procedures to avoid poultry epidemics that can lead to significant economic losses and pose a threat to overall public health. However, despite these procedures, the serology tests performed post-vaccination aren’t always satisfactory, and it's already too late to intervene for preventing disease outbreaks at this stage.

There are many effective vaccines available on the market today for the prevention of a variety of poultry diseases. These vaccines contain weakened or killed antigens with close antigenic similarity to the virus they were designed to prevent. Once injected into the birds' bodies, they stimulate an immunological response, thus enabling the bird to overcome a real virus if exposed to it in the future.

However, even the usage of the best vaccines available can't really ensure flock immunity. This is due to the many misapplication errors that occur throughout the vaccination event. Human error is one of the main factors leading to poor Titer results. Mistakes such as missed or incomplete dose injections, not replacing the needle on time, injections to the wrong injection site, and more can leave the entire flock susceptible to disease outbreaks and lead to induced morbidity and mortality. Therefore, ensuring accurate vaccine administration to each and every bird is a crucial factor in ensuring flock immunity and productivity.

Vaccination crews are required to inject large flocks in short time periods and in poor environmental conditions, which can be stressful for both the birds and the operators. The common tool used for flock vaccination until today was a manual injector. This primitive manual syringe requires extensive effort and attention from the operators to ensure accurate vaccine administration in every shot. Furthermore, due to the strenuous repetitive motion and exposed needle, worker injuries are not uncommon. The lack of ability to control the vaccination process when using the manual syringe can be indicated by poor serology results and can pose a threat to the flock's immunity and health. Another poultry vaccination device available on the market for the past few years is the pHi-Tech vaccination system. This system provides real-time alerts for vaccine misapplications (such as injection of an incorrect dose, missed injections, incorrect vaccine temperature, need to replace the needle or vaccine bottle, incorrect injection site, and more), enabling operators to correct themselves by readministering the shot. It also collects data during the vaccination event, enabling managerial analysis and implementation of data-driven decisions for improvement.

We set out to evaluate if the pHi-Tech vaccination system can help achieve improved vaccination outcomes in comparison to a manual injector. Post-vaccination blood samples were taken from the flocks vaccinated with a manual syringe and with the pHi-Tech vaccination system to examine Titer uniformity and CV at the flock level.

An aerial view of a poultry farm with multiple houses, highlighting two different houses with speech bubbles. One bubble reads 'Manual Injector: 50 birds were not injected, Non-uniform Titers with higher CV' with a question mark, indicating issues with manual vaccination. The other bubble reads 'pHi-Tech: All birds were injected, Uniform Titers and lower CV' with a check mark, showcasing the effectiveness of the pHi-Tech vaccination system.
Contrasting Vaccination Methods: The pHi-Tech system ensures complete vaccination with uniform Titer results, as opposed to the inconsistency seen with manual injectors


In this trial, a total of 2 houses containing 4000 broiler birds in total were vaccinated for EDS to compare the efficiency of the pHi- tech vaccination system vs. a generic manual injector. The post-vaccination comparison analysis showed that no birds were missed in house where pHi-tech was used, whereas 50 birds were missed in the house vaccinated with the manual injector. Furthermore, a serological comparison was conducted indicating of poorer Titer uniformity in the flock vaccinated with the manual injector, whereas the higher Titer uniformity, as measured in the pHi-Tech flock house, indicated of better flock immunity.

Titer Uniformity

Titer tests are used to detect the number of antibodies present in the body. Low Titers indicate of a weakened immunity, meaning that despite being vaccinated, the flock is still susceptible to disease outbreak. The automatic electro-mechanical pump incorporated in the pHi-Tech vaccination system ensured that an accurate and complete dose was administered to every bird in the flock during the vaccination process. In cases where the system detected issues such as an empty vaccine bottle, a blunt needle, incorrect vaccine temperature, early needle pull etc., it immediately alerted the operator and the bird could be re-injected correctly to ensure its immunity. This greatly contributed to the improved serology results shown in the flock vaccinated with pHi-Tech

Close-up of a person's hands wearing blue gloves, drawing a vaccine from a vial into a syringe, set against a blurred white background, illustrating the process of preparing a vaccine for poultry.
Precision in Poultry Health: A vaccine dose being carefully prepared for administration to ensure optimal flock immunity

Coefficient of Variation

The coefficient of variation (CV) is measured in percent and indicates of the ratio of the standard deviation to the mean. A higher CV means there is a greater level of dispersion around the mean. The lower CV shown in the serology results of the flock vaccinated with the pHi-Tech system means that most of the birds showed a high level and uniformity of immunity post-vaccination, whereas the immunity level in the flock vaccinated with the manual injector was more spread-out and un-uniform. Overall, the flock with the higher CV remained more susceptible to disease outbreaks in comparison to the flock vaccinated with the pHi-Tech vaccination system.


This field trial clearly shows that vaccinating poultry with a manual injector leads to unsatisfactory serology results, indicating of compromised flock immunity. A system like pHi-Tech that helps control the vaccination process in real-time misapplication alerts and data collection for analysis can ensure optimal flock immunity and productivity on poultry operations of different scales.



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