美国圣犹大儿童研究医院（St. Jude Children’s Research Hospital）的研究者发现，感冒疫苗似乎能够对致命的禽流感病毒H5N1型有些许抵抗的效果。这项由美国国家过敏与感染疾病研究院（NIAID）与美国黎巴嫩叙利亚联合慈善会（ALSAC）所资助的研究结果，发表于二月13日的PLoS Medicine期刊中。
「一年一次的流行性感冒疫苗，的确具有能够帮助人们对抗禽流感病毒H5N1型侵袭的潜力；」圣犹大儿童研究医院传染疾病部门病毒学科的Richard J. Webby博士表示。
A型流感病毒一般是为具有八个基因区段的RNA病毒，其外套膜上的神经胺酸酶（neuraminidase）与血球凝集素（hemagglutinin）做为分类与命名的依据。H5N1型病毒顾名思义，即为血球凝集素第5型与神经胺酸酶第1型的病毒株。
「一般疫苗的制备，都以较大的血球凝集素作为抗原；」美国食品药物管理局的Matthew Sandbulte博士说。「但研究者提出以神经胺酸酶作为免疫基准的疫苗，似乎相当有意思。」他并指出，以神经胺酸酶作为抗原的疫苗来对付难以估算状况的禽流感是个相当不错的主意。
部分英文原文：
Cross-Reactive Neuraminidase Antibodies Afford Partial Protection against H5N1 in Mice and Are Present in Unexposed Humans
Matthew R. Sandbulte1, Gretchen S. Jimenez2, Adrianus C. M. Boon1, Larry R. Smith2, John J. Treanor3, Richard J. Webby1*
1 Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America, 2 Vical, San Diego, California, United States of America, 3 Infectious Diseases Unit, University of Rochester, Rochester, New York, United States of America
Background
A pandemic H5N1 influenza outbreak would be facilitated by an absence of immunity to the avian-derived virus in the human population. Although this condition is likely in regard to hemagglutinin-mediated immunity, the neuraminidase (NA) of H5N1 viruses (avN1) and of endemic human H1N1 viruses (huN1) are classified in the same serotype. We hypothesized that an immune response to huN1 could mediate cross-protection against H5N1 influenza virus infection.
Methods and Findings
Mice were immunized against the NA of a contemporary human H1N1 strain by DNA vaccination. They were challenged with recombinant A/Puerto Rico/8/34 (PR8) viruses bearing huN1 (PR8-huN1) or avN1 (PR8-avN1) or with H5N1 virus A/Vietnam/1203/04. Additional naïve mice were injected with sera from vaccinated mice prior to H5N1 challenge. Also, serum specimens from humans were analyzed for reactivity with avN1. Immunization elicited a serum IgG response to huN1 and robust protection against the homologous challenge virus. Immunized mice were partially protected from lethal challenge with H5N1 virus or recombinant PR8-avN1. Sera transferred from immunized mice to naïve animals conferred similar protection against H5N1 mortality. Analysis of human sera showed that antibodies able to inhibit the sialidase activity of avN1 exist in some individuals.
Conclusions
These data reveal that humoral immunity elicited by huN1 can partially protect against H5N1 infection in a mammalian host. Our results suggest that a portion of the human population could have some degree of resistance to H5N1 influenza, with the possibility that this could be induced or enhanced through immunization with seasonal influenza vaccines.
更多原文链接：
http://medicine.plosjournals.org/archive/1549-1676/4/2/pdf/10.1371_journal.pmed.0040059-S.pdf
