de Bruijn I A, Nauta J, Cramer W C M, Gerez L, Palache A M
Clinical Development Influenza Vaccines, Solvay Pharmaceuticals BV, PO Box 900, 1380 DA, Weesp, The Netherlands.
Vaccine. 2005 Jul 8;23 Suppl 1:S39-49. doi: 10.1016/j.vaccine.2005.04.020.
Current available influenza vaccines are safe and effective in preventing influenza. Nevertheless, there is a need for influenza vaccines with improved efficacy in the elderly. This need is underscored by both the observation that influenza has a major clinical and economic impact in the elderly and the fact that currently available vaccines are generally less effective in elderly than in younger subjects. Several approaches are currently being pursued in order to improve the efficacy of influenza vaccines in elderly individuals and others who have impaired immune responses to conventional influenza vaccines. A novel antigen-presenting strategy to overcome impaired immune responses is the use of virosomes. Previously, data on safety and reactogenicity have been published regarding the use of virosomal influenza vaccines. Data from three recent clinical trials are presented here. The first of these was a comparative study of a virosomal vaccine and a conventional subunit vaccine in "at-risk" adults with underlying chronic illness. The virosomal vaccine demonstrated comparable tolerability to the subunit vaccine, with about 98% of patients reporting tolerability to be good or very good. The vast majority of adverse events reported were mild to moderate in severity. With both vaccine types, mean HI titres decreased with age for both the A-H1N1 and B influenza virus strains, but for the A-H3N2 strain (the most virulent of the three strains), mean HI titres did not decrease with age, suggesting a better response with the virosomal vaccine when compared to the subunit vaccine. All three studies explored the long-term persistence of antibodies after vaccination with virosomal influenza vaccines. Immunogenicity declined over time but remained high at 4, 6 and 12 months post-vaccination compared to baseline, indicating that adequate seroprotection is achievable for the duration of the influenza season. Virosomal vaccines may induce better immunity in elderly subjects and may be more effective in reducing morbidity and mortality in this age group.
目前可用的流感疫苗在预防流感方面是安全有效的。然而，仍需要在老年人中提高疗效的流感疫苗。流感对老年人有重大临床和经济影响，以及目前可用疫苗在老年人中通常比在年轻受试者中效果更差这两个观察结果都突出了这一需求。目前正在探索几种方法来提高流感疫苗在老年人和其他对传统流感疫苗免疫反应受损者中的疗效。一种克服免疫反应受损的新型抗原呈递策略是使用病毒体。此前，已经发表了关于使用病毒体流感疫苗的安全性和反应原性数据。这里展示了三项近期临床试验的数据。第一项是在患有潜在慢性病的“高危”成年人中对病毒体疫苗和传统亚单位疫苗进行的比较研究。病毒体疫苗显示出与亚单位疫苗相当的耐受性，约98%的患者报告耐受性良好或非常好。报告的绝大多数不良事件严重程度为轻度至中度。对于两种疫苗类型，甲型H1N1和乙型流感病毒株的平均血凝抑制（HI）效价均随年龄下降，但对于甲型H3N2毒株（三种毒株中最具毒性的），平均HI效价并未随年龄下降，这表明与亚单位疫苗相比，病毒体疫苗的反应更好。所有三项研究都探讨了接种病毒体流感疫苗后抗体的长期持久性。免疫原性随时间下降，但与基线相比，在接种后4、6和12个月时仍保持较高水平，表明在流感季节期间可实现足够的血清保护。病毒体疫苗可能在老年受试者中诱导更好的免疫力，并且在降低该年龄组的发病率和死亡率方面可能更有效。
