Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD 20852, USA.
Expert Rev Vaccines. 2010 Nov;9(11):1325-41. doi: 10.1586/erv.10.123.
Antigenic changes in influenza virus occur gradually, owing to mutations (antigenic drift), and abruptly, owing to reassortment among subtypes (antigenic shift). Availability of strain-matched vaccines often lags behind these changes, resulting in a shortfall in public health. In animal models, cross-protection by vaccines based on conserved antigens does not completely prevent infection, but greatly reduces morbidity, mortality, virus replication and, thus, viral shedding and spread. Such immunity is especially effective and long-lasting with mucosal administration. Cross-protective immunity in humans is controversial, but is suggested by some epidemiological findings. 'Universal' vaccines protective against all influenza A viruses might substantially reduce severity of infection and limit spread of disease during outbreaks. These vaccines could be used 'off the shelf' early in an outbreak or pandemic, before strain-matched vaccines are available.
流感病毒的抗原变化是逐渐发生的，这是由于突变（抗原漂移），也是突然发生的，这是由于亚型之间的重配（抗原转变）。由于疫苗株的匹配通常滞后于这些变化，导致公共卫生方面的不足。在动物模型中，基于保守抗原的疫苗的交叉保护并不能完全预防感染，但能大大降低发病率、死亡率、病毒复制，从而减少病毒脱落和传播。这种免疫通过黏膜给药尤其有效且持久。在人类中，交叉保护免疫存在争议，但一些流行病学发现表明存在这种免疫。针对所有甲型流感病毒的“通用”疫苗可能会显著降低感染的严重程度，并限制疾病在暴发期间的传播。这些疫苗可以在暴发或大流行早期“即用型”使用，而无需等待匹配的疫苗株。
