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Chen J, Liu Z, Li K, Li X, Xu L, Zhang M, Wu Y, Liu T, Wang X, Xie S, Xin A, Liao M, Jia W. Emergence of novel avian origin H7N9 viruses after introduction of H7-Re3 and rLN79 vaccine strains to China. Transbound Emerg Dis 2021; 69:213-220. [PMID: 34817918 DOI: 10.1111/tbed.14401] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/14/2021] [Accepted: 11/14/2021] [Indexed: 12/13/2022]
Abstract
In early 2021, roughly 6 months after the H7N9 H7-Re3 and H7N9 rLN79 vaccine strains were introduced into China, we monitored a number of H7N9 subtype avian influenza viruses, which could have escaped vaccine-induced immunity in live poultry markets (LPMs) in Yunnan, Hebei, Shanxi and Guangdong provinces, China. To investigate whether these viruses were a novel H7N9 variant of highly pathogenic avian influenza (HPAI) virus and whether they had the potential for further spread, we characterized the genetic evolution, antigenic divergence and pathogenicity of the viruses in the context of vaccine immunity. The results show further diversification in the HA gene of newly isolated HPAI H7N9 viruses compared with antigenic variants that emerged after the period of 2017-2019. There were clear antigenic differences between current vaccines and these viruses, and SPF broilers under vaccine protection could not resist virus challenges. Our study demonstrates that the current vaccine has insufficient protective capacity against the novel H7N9 variants under experimental conditions. A novel H7N9 immune escape virus has emerged. Faced with potential outbreaks, we should strengthen surveillance and update vaccine strains.
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Affiliation(s)
- Junhong Chen
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Zhaojie Liu
- Research and development center, Guangdong Huasheng Biotechnology Co., Ltd, Guangzhou, China
| | - Ke Li
- Institute of Poultry Management and Diseases, Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan, China
| | - Xiao Li
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Lingyu Xu
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Mengmeng Zhang
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yifan Wu
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Tengfei Liu
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xinkai Wang
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Shumin Xie
- Experimental Animal Center, South China Agricultural University, Guangzhou, China
| | - Aiguo Xin
- Institute of Poultry Management and Diseases, Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan, China
| | - Ming Liao
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis, Key Laboratory of Animal Vaccine Development, Ministry of Agriculture and Rural Affairs, Guangzhou, China
| | - Weixin Jia
- National Avian Influenza Para-Reference Laboratory, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.,Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou, China
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Chakma S, Osmani MG, Akwar H, Hasan Z, Nasrin T, Karim MR, Samad MA, Giasuddin M, Sly P, Islam Z, Debnath NC, Brum E, Magalhães RS. Risk Areas for Influenza A(H5) Environmental Contamination in Live Bird Markets, Dhaka, Bangladesh. Emerg Infect Dis 2021; 27:2399-2408. [PMID: 34424170 PMCID: PMC8386803 DOI: 10.3201/eid2709.204447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
We evaluated the presence of influenza A(H5) virus environmental contamination in live bird markets (LBMs) in Dhaka, Bangladesh. By using Bernoulli generalized linear models and multinomial logistic regression models, we quantified LBM-level factors associated with market work zone–specific influenza A(H5) virus contamination patterns. Results showed higher environmental contamination in LBMs that have wholesale and retail operations compared with retail-only markets (relative risk 0.69, 95% 0.51–0.93; p = 0.012) and in March compared with January (relative risk 2.07, 95% CI 1.44–2.96; p<0.001). Influenza A(H5) environmental contamination remains a public health problem in most LBMs in Dhaka, which underscores the need to implement enhanced biosecurity interventions in LBMs in Bangladesh.
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