去年的甲流来袭让人记忆犹新，国内外针对甲流病毒和甲流疫苗展开了多项研究，中国科学家在其中扮演了重要角色。近期来自上海巴斯德研究所，华兰生物疫苗有限公司的研究人员揭示了甲型H1N1流感疫苗免疫后，抗体应答重要规律，这也许可以作为在疫苗接种前评价甲型H1N1流感疫苗免疫效果的一个指标。这一研究成果公布在国际知名科学杂志PloS ONE上。
领导这一研究的是上海巴斯德所所长孙兵，孙兵博士早年于上海第二医科大学获得免疫学博士学位，90时代曾赴美国NIH做博士后研究，并作为高级访问学者展开研究合作。98年入选中科院“百人计划”，现为美国免疫学家学会会员(American Association of Immunologists; AAI)。
在这篇文章中，上海巴斯德所与华兰生物疫苗有限公司合作进行了甲型H1N1流感疫苗保护性研究，结果发现了人群接种甲型H1N1流感疫苗后，抗体应答产生随时间变化的详细情况，同时初步探讨了甲型H1N1流感疫苗抗体应答与人群中已经存在的季节性流感免疫应答的相互关系。
甲型H1N1流感疫苗可以有效保护人群免受甲型H1N1流感病毒的侵染，但是该疫苗在人体内产生抗体应答的动态变化规律尚未被详细揭示。研究人员为58例健康志愿者接种甲型H1N1流感疫苗，在疫苗免疫前和免疫后第3、5、10、14、21、30、45、60天分别采集志愿者血清，检测了其针对甲型H1N1流感和季节性流感的抗体应答水平。研究发现，早在疫苗接种后第十天，人群即普遍产生针对甲型H1N1流感病毒的免疫保护性（血清保护率：93%），而这一保护性主要由抗流感血凝素HA蛋白的IgG类抗体介导。另外，研究人员还发现，季节性流感抗体应答水平较高的志愿者，在接种甲型H1N1流感疫苗后其产生的针对甲型H1N1流感病毒的保护性抗体滴度也较高，提示人体内已经存在的季节性流感抗体水平也许可以作为在疫苗接种前评价甲型H1N1流感疫苗免疫效果的一个指标。
这一研究是上海巴斯德研究所和华兰生物疫苗有限公司在疫苗研究方面达成战略合作并建立疫苗研发合作实验室后所取得的喜人成果。上海巴斯德所将继续发挥自身的基础研究优势，在疫苗研究领域将产学研一体化，为我国的突发传染病防空战略做出贡献。
原文出处：
PLoS ONE doi:10.1371/journal.pone.0014270
Immune Protection Induced on Day 10 Following Administration of the 2009 A/H1N1 Pandemic Influenza Vaccine
Yizhuo Sun2#, Chao Bian2#, Ke Xu1#, Weibin Hu1, Tongyan Wang1, Jun Cui2, Hongqiang Wu2, Zhiyang Ling2, Yongyong Ji2, Guomei Lin2, Lin Tian2, Yanyan Zhou3, Bingnan Li3, Guiyu Hu1, Ning Yu1, Wenqi An4, Ruowen Pan4, Paul Zhou1, Qibin Leng1, Zhong Huang1, Xiaowei Ma4*, Bing Sun1,2*
1 Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China, 2 Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China, 3 Shanghai Immune Biotech Company, Shanghai, China, 4 Hualan Biological Bacterin Company, Xinxiang, China
Abstract
Background
The 2009 swine-origin influenza virus (S-OIV) H1N1 pandemic has caused more than 18,000 deaths worldwide. Vaccines against the 2009 A/H1N1 influenza virus are useful for preventing infection and controlling the pandemic. The kinetics of the immune response following vaccination with the 2009 A/H1N1 influenza vaccine need further investigation.
Methodology/Principal Findings
58 volunteers were vaccinated with a 2009 A/H1N1 pandemic influenza monovalent split-virus vaccine (15 μg, single-dose). The sera were collected before Day 0 (pre-vaccination) and on Days 3, 5, 10, 14, 21, 30, 45 and 60 post vaccination. Specific antibody responses induced by the vaccination were analyzed using hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA). After administration of the 2009 A/H1N1 influenza vaccine, specific and protective antibody response with a major subtype of IgG was sufficiently developed as early as Day 10 (seroprotection rate: 93%). This specific antibody response could maintain for at least 60 days without significant reduction. Antibody response induced by the 2009 A/H1N1 influenza vaccine could not render protection against seasonal H1N1 influenza (seroconversion rate: 3% on Day 21). However, volunteers with higher pre-existing seasonal influenza antibody levels (pre-vaccination HI titer ≥1:40, Group 1) more easily developed a strong antibody protection effect against the 2009 A/H1N1 influenza vaccine as compared with those showing lower pre-existing seasonal influenza antibody levels (pre-vaccination HI titer &1:40, Group 2). The titer of the specific antibody against the 2009 A/H1N1 influenza was much higher in Group 1 (geometric mean titer: 146 on Day 21) than that in Group 2 (geometric mean titer: 70 on Day 21).
Conclusions/Significance
Recipients could gain sufficient protection as early as 10 days after vaccine administration. The protection could last at least 60 days. Individuals with a stronger pre-existing seasonal influenza antibody response may have a relatively higher potential for developing a stronger humoral immune response after vaccination with the 2009 A/H1N1 pandemic influenza vaccine.
