The HVT strain used to carry and express the “F” gene is known for decades as a very safe and very stable virus, used worldwide to vaccinate chickens against Marek’s disease. The particular NDV strain and passage level selected for the construction of Vectormune® ND ensure an active replication in the chicken and strong expression of the F gene explain why the protection against ND appears so quickly.

The “F” (for “fusion”) protein is the epitope present on the surface of NDV, allowing it to attach and penetrate target cells. It is, at the same time, a key factor of virulence of the virus, as well as a key protective antigen. One can easily understand that if immunity is built up against “F” protein, then NDV would have much more difficulties to infect cells and create damage. This is explaining the high efficacy of Vectormune® ND. 

The poultry industry is changing extremely fast and its challenges have increased considerably over the years. For producers, efficiency, rather than a differentiating point, became a survival strategy.

Today, it is necessary to produce ‘more with less’ and in a context of a challenging environment. In addition, high diseases pressure, high stocking density in farms located in very densely populated areas, poorly qualified workers, pressure to reduce use of antibiotics and others are daily challenges faced by all involved in this industry.

Vectormune® ND is the best in class solution to overcome the below concerns where the other ND vaccines are not enough:

1. Interference with Maternally Derived Antibodies (MDA)
2. Challenges of vaccine administration
3. Side effects
4. Virus circulation

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Onset of immunity

An antibody response to Vectormune® ND (of the type IgG, IgM and IgA) can be detected in SPF chickens as soon as 9-12 days post vaccination (Rauw et al., 2012).

The immune response to Vectormune® ND is not only composed of circulating antibodies but also of a local immune response. It is not only humoral but also cellular (Rauw et al., 2010). Antibody response to Vectormune® ND can be detected using the  Haemagglutination Inhibition (HI) test, or ND “F” ELISA tests.

Following vaccination at day one, in the presence of passive immunity, antibody response can be clearly differentiated from the controls at around 21-28 days of age. On the reverse, this detection is not possible with commercial ND ELISA kits (E.g.: Idexx, Biochek). If no live vaccine is used, this can be a simple serological method to differentiate vaccinated only from vaccinated and infected or simply or simply infected animals (commonly known as “DIVA procedure”).

Duration of immunity

Duration of immunity is probably the most impressive feature of this vaccine.

Following a single injection of Vectormune® ND at day of hatch, layers are totally protected against clinical signs, mortality and drop in egg production until, at least, 72 weeks of age (Palya et al., 2012c). This cannot be compared to any existing ND vaccination conventional program where a minimum of 2 to 4 killed and 5 to 8 live vaccinations would be necessary to achieve acceptable (but not comparable) level of protection.

Reduction of Shedding

A proven reference for the reduction of Newcastle disease transmission

Vectormune® ND is a strong tool to break the uncontrolled transmission of NDV among chickens in a house, in between houses in a farm, and ultimately among farms in a high densely populated poultry area. Hence, Vectormune® ND helps to prevent and control Newcastle Disease outbreaks in poultry industry and protects the performance. By this way, Ceva Animal Health provides one more evidence towards supporting its customers to achieve their targets all around the world.

Vaccination strategy

Since protection with Vectormune® ND requires replication of the HVT vector and this generally takes some days, the first 3 weeks of life are gradually covered by Vectormune® ND.

For this reason, in ND endemic countries, the vaccination strategy with Vectormune® ND requires ensuring early protection by application of a live attenuated ND vaccine by spray on the first day of age in the hatchery. In order to avoid damages to the trachea, which are detrimental to both growth and the integrity of the respiratory tract, it is strongly recommended to use a vaccine based on an apathogenic enterotropic NDV strain, like the Phy.LMV.42 NDV strain present in Cevac® Vitapest L (ND only) or Cevac® Vitabron L (combination of ND + IB).

In countries where ND is only an epizootic risk, it is advisable to remove any live ND vaccine from the program. The combination of a reliable ND passive immunity together with Vectormune® ND induced active immunity will ensure a very significant level of protection. By removing the use of any live ND vaccine in chicken flocks, this innovative approach helps to improve the overall respiratory health, which could in turn result in less antibiotic medication and lower rates of airsacculitis at the processing plant. 

Following several years of investigation with Vectormune® ND, we believe that this vaccine is more a revolution than a simple evolution.

Vectormune® ND has been changing the approach of Newcastle disease prevention in the field and is being considered as a strong tool towards the long term control of this important poultry disease.

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