Center of Scientific Excellence for Influenza Viruses, National Research Center, Giza, Egypt.
Biotechnology Research Group, Department of Biological Sciences, Faculty of Science, King Abdulaziz University (KAU), Jeddah, 21589, Saudi Arabia.
Sci Rep. 2018 Jun 26;8(1):9697. doi: 10.1038/s41598-018-28057-x.
The newly emerging, highly pathogenic avian influenza (HPAI) H5N8 virus of clade 2.3.4.4 was recently detected in wild birds and domestic poultry in Egypt in the 2016/2017 winter season. Vaccination based on commercial H5 vaccines is used as an essential control strategy in Egyptian poultry. Here, we studied the efficacy of the eight most common commercial H5 poultry vaccines in the Egyptian market and compared them with an experimental vaccine based on the Egyptian LPAI H5N8 virus that was prepared by using reverse genetics. The experimental vaccine and Re-5 commercial vaccine were able to completely protect chickens and significantly reduce virus shedding. Our results indicate that most of the commercial poultry H5 vaccines used in the present study were ineffective because the seed viruses in these vaccines are genetically distinct from the H5N8 viruses currently circulating in Egypt. Although some of the commercial vaccines protected chickens from mortality, they failed to prevent chickens from shedding the virus. Accordingly, we recommend updating and reinforcing the H5N8 prevention and control strategies in Egypt. The vaccination strategy should be reconsidered based on currently circulating viruses.
最近在 2016/2017 年冬季，埃及的野生鸟类和家禽中检测到了新兴的高致病性禽流感（HPAI）H5N8 病毒，该病毒属于 2.3.4.4 分支。基于商业 H5 疫苗的接种被用作埃及家禽的重要控制策略。在这里，我们研究了埃及市场上 8 种最常见的商业 H5 家禽疫苗的功效，并将其与基于反向遗传学制备的埃及低致病性禽流感（LPAI）H5N8 病毒的实验疫苗进行了比较。实验疫苗和 Re-5 商业疫苗能够完全保护鸡并显著减少病毒脱落。我们的研究结果表明，目前研究中使用的大多数商业家禽 H5 疫苗均无效，因为这些疫苗中的种子病毒在遗传上与目前在埃及流行的 H5N8 病毒不同。尽管一些商业疫苗能够保护鸡免于死亡，但它们未能阻止鸡传播病毒。因此，我们建议更新和加强埃及的 H5N8 预防和控制策略。应根据当前流行的病毒重新考虑疫苗接种策略。
