Global EditionASIA 中文雙語Fran?ais
    China
    Home / China / Innovation

    Scientists discover how H5N1 virus invades cattle

    By Zhao Yimeng | China Daily | Updated: 2025-07-08 09:32
    Share
    Share - WeChat

    Chinese scientists say they have uncovered how the H5N1 virus initially invades the mammary glands of dairy cattle, potentially triggering last year's outbreak of bird flu across more than 1,000 dairy farms in the United States.

    The study, published recently in the journal National Science Review, was conducted by the Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences in Heilongjiang province. Researchers found that tissues in the mouths of cattle support H5N1 virus binding and replication, allowing the virus to spread to the mammary glands during suckling.

    Chen Hualan, an academician with the Chinese Academy of Sciences and a chief scientist at the institute, and her team also confirmed that vaccination provides full protection against the virus in dairy cows. The study suggests that targeted control of milk-stealing behavior and immunization could help curb H5N1 outbreaks among cattle.

    Highly pathogenic bird flu subtype H5N1 is a major zoonotic disease, transmissible from animals to humans under natural conditions. Since 2021, a new strain has caused tens of thousands of outbreaks among poultry and wild birds worldwide.

    In March last year, the virus began infecting dairy cows in the US. As of June 7 this year, infections have been reported on more than 1,070 dairy farms across 17 states, with cow-to-cow transmission suspected during milking, according to the study.

    The outbreaks have resulted in a cow mortality rate of up to 10 percent and infected at least 41 farmworkers, raising concerns about dairy production and public health.

    Previous research found that H5N1 can damage cows' mammary glands and contaminate milk, with about one-fourth of retail milk samples in the US testing positive for the virus. However, it was unclear how the virus initially entered the mammary glands, and no effective control measures were available.

    The new findings shed light on the virus' transmission routes in cattle, Chen said. The study revealed that cows' oral tissues are rich in sialic acid receptors, which are key binding sites for H5N1, making cattle vulnerable to infection through contaminated feed and water. The virus can replicate and remain in the mouth for several days. Behaviors such as self-suckling and cross-suckling from other cows can enable oral-to-udder transmission of the virus, the study found.

    Vaccination has been central to controlling highly pathogenic bird flu in China since 2004, with anti-genically well-matched vaccines providing complete protection in poultry. Applying this approach to cattle could be an effective and economical way to halt H5N1 transmission and reduce its threat to public health, Chen said.

    "We found that either an inactivated H5 vaccine or a hemagglutinin-based DNA vaccine could induce sterilizing immunity in cows against challenges from multiple H5N1 virus strains," she said.

    Inactivated and DNA vaccines could prevent both naturally occurring H5N1 infections in cattle and mammary gland infections caused by high-dose virus exposure during milking, Chen said.

    Top
    BACK TO THE TOP
    English
    Copyright 1995 - . All rights reserved. The content (including but not limited to text, photo, multimedia information, etc) published in this site belongs to China Daily Information Co (CDIC). Without written authorization from CDIC, such content shall not be republished or used in any form. Note: Browsers with 1024*768 or higher resolution are suggested for this site.
    License for publishing multimedia online 0108263

    Registration Number: 130349
    FOLLOW US
     
    中文人妻无码一区二区三区| 久久亚洲中文字幕精品一区四 | 国产av无码专区亚洲av桃花庵| 亚洲av无码天堂一区二区三区| 亚洲VA中文字幕不卡无码| 中文字幕日韩欧美一区二区三区| YY111111少妇无码理论片| 亚洲A∨无码无在线观看| 中文成人无码精品久久久不卡| 亚洲中文字幕日产乱码高清app| 国产精品多人p群无码| 亚洲AV无码国产丝袜在线观看| 天堂Aⅴ无码一区二区三区 | 久久精品中文字幕久久| 国产精品热久久无码av| 无码夫の前で人妻を犯す中字| 日本中文字幕网站| 中文字幕无码无码专区| 亚洲高清无码在线观看| 亚洲成A人片在线观看无码3D | 欧美 亚洲 有码中文字幕| AV无码精品一区二区三区| 精品久久久久久久无码| 人妻中文字幕无码专区| 色情无码WWW视频无码区小黄鸭| 亚洲AV日韩AV高潮无码专区| 中文字幕人妻无码一区二区三区 | 中文字幕无码精品三级在线电影| 白嫩少妇激情无码| 无码人妻精品一区二区三区99性| 国产高清中文欧美| 亚洲天堂中文字幕| 中文成人久久久久影院免费观看| 中文字幕手机在线观看| 亚洲国产精品无码中文字| 亚洲日韩激情无码一区| 午夜福利无码不卡在线观看 | MM1313亚洲精品无码| 精品久久久久久无码中文野结衣| 久久久久成人精品无码| 中文字幕丰满乱孑伦无码专区|