Format

Send to

Choose Destination
Vet Immunol Immunopathol. 2017 Sep;191:74-79. doi: 10.1016/j.vetimm.2017.08.001. Epub 2017 Aug 10.

Protection of commercial turkeys following inactivated or recombinant H5 vaccine application against the 2015U.S. H5N2 clade 2.3.4.4 highly pathogenic avian influenza virus.

Author information

1
Exotic and Emerging Avian Viral Diseases Research Unit, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, 934 College Station Road, Athens, GA, 30605, United States. Electronic address: darrell.kapczynski@usda.ars.gov.
2
Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, 1920 Dayton Avenue, Ames, IA, 50010, United States.
3
National Veterinary Services Laboratories, Veterinary Services, Animal and Plant Health Inspection Service, U.S. Department of Agriculture, Ames, IA 50010, United States.
4
Exotic and Emerging Avian Viral Diseases Research Unit, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, 934 College Station Road, Athens, GA, 30605, United States.

Abstract

Between December 2014 and June 2015, North America experienced the largest recorded foreign animal disease outbreak with over 47 million poultry dead or euthanized from viral exposure to a clade 2.3.4.4 H5 highly pathogenic avian influenza (HPAI) epizootic. Soon after the epizootic began, the U.S. Department of Agriculture (USDA) began testing the efficacy of different vaccines as a possible future control strategy. The aim of these studies were to evaluate the efficacy three H5 vaccines to aid in control of HPAI in commercial turkeys. Three different vaccine technologies were evaluated for efficacy: 1) inactivated reverse genetic laboratory-generated virus encoding a clade 2.3.4.4 H5 hemagglutinin (HA) gene (rgH5), 2) recombinant turkey herpesvirus encoding a clade 2.2. H5 HA (rHVT-AI), and 3) recombinant replication-deficient alphavirus RNA particle vaccine encoding a clade 2.3.4.4 H5 HA (RP-H5). All vaccines tested significantly (P<0.01) increased survival rates between vaccinated and sham vaccinated groups of poults challenged with A/turkey/Minnesota/12582/2015 clade 2.3.4.4 H5N2 HPAI. The rgH5 vaccine had detectable serum hemagglutination inhibition (HI) antibody against the challenge virus, and significantly reduced the frequency and level of viral shedding from oropharyngeal and cloacal swabs at days 2 and 4 post-challenge. Vaccination with only rHVT-AI or RP-H5 was not 100% protective, and failed to significantly reduce viral shedding post-challenge. A combined prime and boost strategy with the rHVT-AI and RP-H5, or rHVT-AI and rgH5, was 100% protective against lethal H5N2 HPAI challenge. Results of these studies led to USDA conditional approval of commercially available recombinant vaccines for use in turkeys as a control measure for clade 2.3.4.4 H5 HPAI epizootics.

KEYWORDS:

Highly pathogenic avian influenza virus; Recombinant vaccine; Reverse genetics; Turkey (Meleagris gallopavo); Vaccine efficacy; Viral shedding

PMID:
28895870
DOI:
10.1016/j.vetimm.2017.08.001
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center