#Immunization with live nonpathogenic #H5N3 #duck #influenza virus protects #chickens against highly pathogenic #H5N1 virus (Acta Virol., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Acta Virol. 2016;60(3):316-27.

Immunization with live nonpathogenic H5N3 duck influenza virus protects chickens against highly pathogenic H5N1 virus.

Gambaryan AS, Boravleva EY, Lomakina NF, Kropotkina EA, Gordeychuk IV, Chvala IA, Drygin VV, Klenk HD, Matrosovich MN.

 

Abstract

Development of an effective, broadly-active and safe vaccine for protection of poultry from H5N1 highly pathogenic avian influenza viruses (HPAIVs) remains an important practical goal. In this study we used a low pathogenic wild aquatic bird virus isolate А/duck/Moscow/4182/2010 (H5N3) (dk/4182) as a live candidate vaccine. We compared this virus with four live 1:7 reassortant anti-H5N1 candidate vaccine viruses with modified hemagglutinin from either A/Vietnam/1203/04 (H5N1) or A/Kurgan/3/05 (H5N1) and the rest of the genes from either H2N2 cold-adapted master strain A/Leningrad/134/17/57 (rVN-Len and rKu-Len) or H6N2 virus A/gull/Moscow/3100/2006 (rVN-gull and rKu-gull). The viruses were tested in parallel for pathogenicity, immunogenicity and protective effectiveness in chickens using aerosol, intranasal and oral routes of immunization. All five viruses showed zero pathogenicity indexes in chickens. Viruses rVN-gull and rKu-gull were immunogenic and protective, but they were insufficiently attenuated and caused significant mortality of 1-day-old chickens. The viruses with cold-adapted backbones (rVN-Len and rKu-Len) were completely nonpathogenic, but they were significantly less immunogenic and provided lower protection against lethal challenge with HPAIV A/Chicken/Kurgan/3/05 (H5N1) as compared with three other vaccine candidates. Unlike other four viruses, dk/4182 was both safe and highly immunogenic in chickens of any age regardless of inoculation route. Single administration of 106 TCID50 of dk/4182 virus via drinking water provided complete protection of 30-days-old chickens from 100 LD50 of the challenge virus. Our results suggest that low pathogenic viruses of wild aquatic birds can be used as safe and effective live poultry vaccines against highly pathogenic avian viruses.

KEYWORDS: influenza virus A; H5N1; poultry vaccine.

PMID: 27640442

[PubMed – in process]

Keywords: Research; Abstracts; Avian Influenza; h5N1; H5N2; Vaccines.

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#Lessons from the Largest #Epidemic of #Avian #Influenza Viruses in #Taiwan, 2015 (Avian Dis., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Avian Dis. 2016 May;60(1s):156-171.

Lessons from the Largest Epidemic of Avian Influenza Viruses in Taiwan, 2015.

Chang CF1, King CC2, Wan CH3, Chang YC2, Chan TC4, David Lee CC2,5, Chou PB2, Li ZT2, Li YT2, Tseng TJ2,6, Lee PF7, Chang CH1.

Author information: 1A Institute of Biomedical Informatics, National Yang-Ming University, Taipei, Taiwan, Republic of China. 2B Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan (100), Republic of China. 3C Institute of Molecular & Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan (106), Republic of China. 4D Research Center for Humanities and Social Sciences, Academia Sinica, Taipei, Taiwan (115), Republic of China. 5E Genomics Research Center, Academia Sinica, Taipei, Taiwan (115), Republic of China. 6F Department of Public Health, College of Medicine, Fu Jen Catholic University, New Taipei, Taiwan (242), Republic of China. 7G Institute of Ecology and Evolutionary Biology, College of Life Sciences, National Taiwan University, Taipei, Taiwan (106), Republic of China.

 

Abstract

The largest epidemic of avian influenza (AI) in history attacked poultry and wild birds throughout Taiwan starting January 6, 2015. This study analyzed surveillance results, epidemiologic characteristics, and viral sequences by using government-released information, with the intention to provide recommendations to minimize future pandemic influenza. The H5 clade 2.3.4.4 highly pathogenic AI viruses (HPAIVs) had not been detected in Taiwan before 2015. During this epidemic, four types of etiologic agents were identified: the three novel subtypes H5N2, H5N8, and H5N3 clade 2.3.4.4 HPAIVs and one endemic chicken H5N2 subtype (Mexican-like lineage) of low pathogenic AI viruses. Cocirculation of mixed subtypes also occurred, with H5N2 clade 2.3.4.4 HPAIVs accompanied by the H5N8 and H5N3 subtypes or old H5N2 viruses in the same farm. More than 90% of domestic geese died from this AI epidemic; geese were affected the most at the early outbreaks. The epidemic peaked in mid-January for all three novel H5 subtypes. Spatial epidemiology found that most affected areas were located in southwestern coastal areas. In terrestrial poultry (mostly chickens), different geographic distributions of AI virus subtypes were detected, with hot spots of H5N2 clade 2.3.4.4 vs. past-endemic old H5N2 viruses in Changhwa (P = 0.03) and Yunlin (P = 0.007) counties, respectively, of central Taiwan. Phylogenetic and sequence analyses of all the early 10 Taiwan H5 clade 2.3.4.4 isolates covering the three subtypes showed that they were very different from the HA of the past local H5 viruses from domestic ducks (75%-80%) and chickens (70%-75%). However, they had the highest sequence identity percentages (99.53%-100%), with the HA of A/crane/Kagoshima/KU13/2014(H5N8) isolated on December 7, 2014, in Japan being higher than those of recent American and Korean H5 HPAIVs [A/Northern pintail/Washington/40964/2014 (H5N2) and A/gyrfalcon/Washington/41088-6/2014 (H5N8): 99.02%-99.54% and A/Baikal teal/Korea/Donglim3/2014 (H5N8): 98.61%-99.08%], implying a likely common ancestor of these H5 clade 2.3.4.4 viruses. The multiple subtypes of H5 clade 2.3.4.4 HPAIVs imply high viral reassortment. We recommend establishing an integrated surveillance system, involving clinical, virologic, and serologic surveillance in poultry and wild birds, swine and other mammals prevalent on multiple-animal mixed-type traditional farms, and high-risk human populations, as a crucially important step to minimize future pandemic influenza.

KEYWORDS: Taiwan; epidemiology; highly pathogenic avian influenza H5 virus; phylogenetic analysis; prevention and control policy; surveillance

PMID: 27309051 [PubMed – as supplied by publisher]

Keywords: Research; Abstracts; Avian Influenza; H5N2; H5N8; H5N2; Poultry; Taiwan.

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