Department of Health Science, University of Genoa (Italy), Via Pastore, 1-16132, Genoa, Italy.
Expert Rev Vaccines. 2012 Feb;11(2):145-57. doi: 10.1586/erv.11.170.
Influenza viruses are adept in human populations. Indeed, they have the capacity to evade the immune system through mechanisms of mutations (antigenic drift) and major variations in surface protein expression (antigenic shift). When a major change occurs, the risk of a human pandemic arises. Three influenza pandemics occurred during the 20th century, the most serious being the Spanish influenza. The last pandemic of the past century occurred in 1968, and the responsible virus infected an estimated 1-3 million people throughout the world. The first pandemic of the present century occurred in 2009 and was sustained by a H1N1 strain (A/California/07/09). In 1997, a novel avian influenza virus, H5N1, first infected humans in China. Since its emergence, the H5N1 virus has spread from Asia to Europe and Africa, resulting in the infection of millions of poultry and wild birds. So far, 522 human cases and 322 deaths have been reported by the WHO. Many studies have therefore been performed to obtain efficacious and safe H5N1 vaccines. One of these is Aflunov(®). Aflunov is a prepandemic monovalent A/H5N1 influenza vaccine adjuvanted with MF59 produced by Novartis Vaccines and Diagnostics. In nonclinical studies conducted in rabbits, Aflunov proved to be well-tolerated, did not cause maternal or embryo-fetal toxicity, was not teratogenic, and had no effects on postnatal development. In clinical studies, Aflunov proved safe and well-tolerated in infants, children, adolescents, adults and the elderly. In the same subjects, the vaccine elicited robust immunogenicity against both homologous (A/Vietnam/1194/2004 clade 1) and heterologous viral strains (for instance, A/Indonesia/05/2005 or A/Turkey/15/2006) and induced immunologic memory. Thus, in 2010, the CHMP issued a positive opinion on Aflunov and in January 2011 Aflunov was given marketing authorization. This vaccine could be very useful in the event of adaptation of the H5N1 virus to humans, which could cause a new pandemic.
流感病毒在人类群体中非常活跃。事实上，它们有能力通过突变（抗原漂移）和表面蛋白表达的主要变化（抗原转变）来逃避免疫系统。当发生重大变化时，就会出现人类大流行的风险。 20 世纪发生了三次流感大流行，其中最严重的是西班牙流感。上世纪最后一次大流行发生在 1968 年，据估计，当时全球有 100 万至 300 万人感染了这种病毒。本世纪第一次大流行发生在 2009 年，由 H1N1 株（A/California/07/09）引起。 1997 年，一种新型禽流感病毒 H5N1 首次在中国感染人类。自出现以来，H5N1 病毒已从亚洲传播到欧洲和非洲，导致数以百万计的家禽和野鸟感染。到目前为止，世界卫生组织已报告了 522 例人类病例和 322 例死亡。因此，已经进行了许多研究来获得有效和安全的 H5N1 疫苗。其中之一是 Aflunov（®）。 Aflunov 是一种由诺华疫苗和诊断公司生产的含佐剂的季节性单价 A/H5N1 流感疫苗 MF59。在兔子进行的非临床研究中，Aflunov 被证明具有良好的耐受性，不会引起母体或胚胎胎儿毒性，无致畸性，并且对产后发育没有影响。在临床试验中，Aflunov 在婴儿、儿童、青少年、成人和老年人中均安全且耐受良好。在相同的研究对象中，该疫苗对同源（A/Vietnam/1194/2004 分支 1）和异源病毒株（例如，A/Indonesia/05/2005 或 A/Turkey/15/2006）均产生了强大的免疫原性，并诱导了免疫记忆。因此，2010 年，CHMP 对 Aflunov 发表了积极意见，2011 年 1 月，Aflunov 获得了营销授权。如果 H5N1 病毒适应人类，可能会引发新的大流行，这种疫苗将非常有用。
