23 June 2015, Libourne, France: A paper* recently published in the peer-reviewed journal Vaccine** reports that Ceva’s new generation vaccine, Vectormune® AI, offers significant advantages over previously available vaccines against highly pathogenic avian influenza (HPAI).
The authors conclude that, combined with effective biosecurity measures and monitoring, Vectormune® AI is a useful tool to control different types of HPAI of the H5 serotype in chickens.
Previously, most avian influenza vaccines have been crude inactivated whole virus vaccines. These vaccines provide good protection only against virus types that are identical to those used to make the vaccine. They can also be rendered ineffective in the presence of maternally derived antibodies (MDAs), which are transferred from the vaccinated hen to the embryo and can persist in chicks for up to 4 weeks.
In contrast, Ceva’s Vectormune® AI is a vector vaccine. It is based on a well-known and safe turkey herpes virus (Marek’s HVT), which has been modified to carry the H5 type hemagglutinin antigen, the key protective factor against the avian influenza virus, which is the key protective factor. The result of the described modification is that this vaccine produces solid immunity against AI viruses of the H5 serotype.
Protection of the vaccinated bird is due to induction of neutralizing antibodies directed against the hemagglutinin as well as stimulation of a cellular immune response, which is not present when classical inactivated vaccines are used. This explains the high efficacy of the vaccine as well as its broad spectrum of protection against all AI virus strains of the H5 serotype that have so far been tested.
Vectormune® AI is also effective in the presence of MDAs. It can therefore be effectively administered to day-old chicks at the hatchery. This eliminates problems associated with the variable quality of vaccine administration on the farm and provides life-long protection.
Avian influenza is considered to be one of the most detrimental diseases of poultry that can also, under particular conditions, be transmitted from birds to people. Since 2003, the H5N1 strain of the disease has killed a reported 447 people while the economic impact of the disease runs into billions with hundreds of millions of birds having been culled worldwide.***
For more information see Vectormune® AI at www.vectormune-ai.com.
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*Vaccine protection of chickens against antigenically diverse H5 highly pathogenic avian influenza isolates with a live HVT vector vaccine expressing the influenza hemagglutinin gene derived from a clade 2.2 avian influenza virus was written by:
- Darrell R. Kapczynski and Haijun Jianga, Exotic and Emerging Avian Disease Research Unit, Southeast Poultry Research Laboratory, Agricultural Research Service, USDA, 934 College Station Road,Athens, GA 30605, United States
- Motoyuki Esaki, Kristi M. Dorsey and Mauro Moraes, Ceva Animal Health, Lenexa, KS, United States
- Mark Jackwood, Department of Population Health, College of Veterinary Medicine, The University of Georgia, Athens, GA, United States
- Yannick Gardin, Ceva Animal Health, Libourne, France
The paper was published in January 2015. The reference is: Vaccine 33 (2015) 1197–1205. The full text is available online: http://www.ncbi.nlm.nih.gov/pubmed/25613723
**Vaccine, the official journal of The Edward Jenner Society, The International Society for Vaccines and The Japanese Society for Vaccinology, is the pre-eminent journal for those interested in vaccines and vaccination.
***WHO/GIP, 1 May 2015 www.who.int/influenza/human_animal_interface/EN_GIP_20150501CumulativeNumberH5N1cases.pdf