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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Exotic & Emerging Avian Viral Diseases Research » Research » Publications at this Location » Publication #341172

Research Project: Intervention Strategies to Prevent and Control Disease Outbreaks Caused by Emerging Strains of Avian Influenza Viruses

Location: Exotic & Emerging Avian Viral Diseases Research

Title: Short- and long-term protective efficacy against clade 2.3.4.4 H5N2 highly pathogenic avian influenza virus following prime-boost vaccination in turkeys

Author
item Santos, Jefferson - University Of Georgia
item Obadan, Adebimpe - University Of Georgia
item Cardenas Garcia, Stivalis - University Of Georgia
item Carnaccini, Silvia - University Of Georgia
item Pantin-jackwood, Mary
item Suarez, David
item Kapczynski, Darrell
item Perez, Daniel - University Of Georgia

Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/19/2017
Publication Date: 9/6/2017
Publication URL: http://handle.nal.usda.gov/10113/5831658
Citation: Santos, J., Obadan, A., Cardenas Garcia, S., Carnaccini, S., Pantin Jackwood, M.J., Suarez, D.L., Kapczynski, D.R., Perez, D.R. 2017. Short- and long-term protective efficacy against clade 2.3.4.4 H5N2 highly pathogenic avian influenza virus following prime-boost vaccination in turkeys. Vaccine. 35:5637-5643. http://dx.doi.org/10.1016/j.vaccine.2017.08.059.

Interpretive Summary: In 2014-2015, H5N2 highly pathogenic avian influenza (HPAI) virus, clade 2.3.4.4, caused a devastating outbreak in poultry in the United States. Meat turkey and laying hen production systems in the Midwest were particularly affected, causing the largest animal health emergency in recent history in the U.S. In this study, the efficacy of 2 vaccines was examined for reduction of virus shedding and clinical signs of disease in turkeys at 6 and 16 weeks of age challenged with a clade 2.3.4.4 H5N2 HPAI virus. Three different vaccine regimes were used. Vaccinated turkeys showed significantly reduced virus shedding and mortality compared to unvaccinated control birds. However, the timing between vaccination and challenge affected the protective efficacy of the vaccine regimes tested. Our study highlights the importance of studying not only different vaccine platforms but also vaccination strategies to maximize protection against HPAIV.

Technical Abstract: Highly pathogenic avian influenza virus (HPAIV) infections are frequently associated with systemic disease and high mortality in domestic poultry, particularly in chickens and turkeys. Clade 2.3.4.4 represents a genetic cluster within the Asian HPAIV H5 Goose/Guangdong lineage that has spread through migratory birds and diversified throughout the world. In 2014, clade 2.3.4.4 strains entered the U.S. via the Pacific flyway, reassorted with local strains of the North American lineage, and produced novel HPAIV strains of the H5N1, H5N2, and H5N8 subtypes. By 2015, the H5N2 HPAIVs disseminated eastwards within the continental U.S. and Canada and entered into commercial poultry. Meat turkey and laying hen production systems in the Midwest were particularly affected, causing the largest animal health emergency in recent history in the U.S. Using a prime-boost approach, we evaluated the efficacy of 2 vaccines in reducing virus shedding and clinical signs of disease in turkeys at 6 and 16 weeks of age challenged with a prototypic novel clade 2.3.4.4 H5N2 HPAIV. Three different vaccine regimes were used. After challenge, vaccinated turkeys showed significantly reduced virus shedding and mortality compared to unvaccinated control birds. Interestingly, the timing between vaccination and challenge revealed important differences in the protective efficacy of the vaccine regimes tested. Our study highlights the importance of studying not only different vaccine platforms but also vaccination strategies to maximize protection against HPAIV especially with regards to the longevity of vaccine-induced immune response.