新城疫病毒的进化及其新型疫苗的研制

新城疫病毒（NDV）虽然只有一个血清型，但其强毒已进化出现了九个基因型。近年来，ND疫苗在世界范围内得到了广泛使用，但免疫鸡群中ND强毒感染仍然常见。常用疫苗株LaSota对不同基因型的ND强毒流行株虽能产生完全的临床保护，但并不能防止流行株在免疫鸡中的感染复制和排出。国内外研究结果显示：当疫苗株与流行株的基因型一致时，其不仅能提供理想的临床保护，而且能显著降低免疫鸡的强毒感染率和排毒量，在临床上可有效控制免疫鸡群中非典型ND的发生。当前我国NDV的优势流行株属基因VII型，因此该型ND疫苗在控制我国ND的流行中将具有非常广阔的应用前景。

Evolution of Newcastle Disease Virus and the Development of Novel Vaccines

Virulent Newcastle disease viruses (NDV) have evolved into nine genotypes although they belong to one serotype. In recent years, vaccination has been used extensively in the world for the prevention and control of ND, however, virulent NDV infection in vaccinated birds still occurred frequently. The commonly used vaccine strain La Sota can provide complete clinical protection against the prevalent strains of different genotypes, but can not prevent their infection, replication and shedding. Recent studies showed that the vaccine strain sharing the same genotype with the prevalent NDV not only provided ideal clinical protection but also effectively reduced the infection rate and shedding of the prevalent strain. Presently, the dominant prevalent NDV strains in China belong to genotype VII. Therefore this genotype-based vaccine will be a promising vaccine candidate for the control of current ND epidemic in China.