Science：禽用疫苗产生了强毒力菌株

刊登在国际杂志<em>Science</em>上的一项研究中，研究人员在报告说，用于禽类疫苗中的多个修改过的疱疹病毒株混合了它们的基因组，产生出了一种新的强毒力株，该强毒力株导致澳大利亚大量鸡只的死亡。

这些发现主要对兽医学及未来动物疫苗的研发以避免类似情况的出现有重要影响。活的“减毒”疱疹病毒疫苗所用的是一种经过设计的毒性较弱但仍然能够复制的疱疹病毒；这类疫苗被广泛用于人类医学和兽医学中。据Sang-Won Lee及其同事披露，研究人员曾经对某种活的减毒疫苗可能会与其它病毒株重组而产生一种新的、强毒力株表示关切，但由疱疹病毒疫苗重组引起疾病的爆发还从来没有被报道过。

<!--more-->

两种新的、基因型不同的疱疹病毒，即传染性喉气管炎病毒或ILTV最近在澳大利亚的家禽业中出现，并造成高达17.6%的死亡率。在澳大利亚可以得到3种不同的活的减毒ILTV疫苗，其中一种带有一个来自欧洲的病毒株，2个带有澳大利亚的病毒株。Lee及其同事对该新病毒的基因组进行了测序并将其与这3种疫苗株进行了比较。其结果与疫苗病毒株的重组产生了2种新的强毒力株的可能性是一致的。 
<div id="ztload">
<div>
<div>

<img src="http://www.bioon.com/biology/UploadFiles/201207/2012071322053809.jpg" alt="" width="113" height="149" border="0" />

<a title="" href="http://dx.doi.org/doi:10.1126/science.1217134" target="_blank">doi:10.1126/science.1217134</a>
PMC:
PMID:

</div>
<div>

<br/><strong>Attenuated Vaccines Can Recombine to Form Virulent Field Viruses</strong><br/>


Sang-Won Lee1, Philip F. Markham1, Mauricio J. C. Coppo1, Alistair R. Legione1, John F. Markham3, Amir H. Noormohammadi2, Glenn F. Browning1, Nino Ficorilli1, Carol A. Hartley1, Joanne M. Devlin1,*

&nbsp;

Recombination between herpesviruses has been seen in vitro and in vivo under experimental conditions. This has raised safety concerns about using attenuated herpesvirus vaccines in human and veterinary medicine and adds to other known concerns associated with their use, including reversion to virulence and disease arising from recurrent reactivation of lifelong chronic infection. We used high-throughput sequencing to investigate relationships between emergent field strains and vaccine strains of infectious laryngotracheitis virus (ILTV, gallid herpesvirus 1). We show that independent recombination events between distinct attenuated vaccine strains resulted in virulent recombinant viruses that became the dominant strains responsible for widespread disease in Australian commercial poultry flocks. These findings highlight the risks of using multiple different attenuated herpesvirus vaccines, or vectors, in the same populations.

<br/>来源：EurekAlert!

</div>
</div>
</div>