PDF(Pubmed)
Abstract：
World Health Organization (WHO) recommended 2 doses of the Human Papillomavirus (HPV) vaccine for girls below 15 y on the basis of the immune-bridging studies demonstrating non-inferior immune response of 2 doses in the adolescent girls compared to 3 doses in the young adult women in whom the efficacy against disease is established. The biological nature of the antigens (virus-like particles) constituting the HPV vaccine is responsible for the vigorous antibody response that may make the third dose redundant. The protection offered by 2 doses has been demonstrated in non-randomized clinical trials to be comparable to that offered by 3 doses against incident and persistent infections of vaccine targeted HPV types. However, results emerging from the ecological and nested case-control studies embedded in the population based screening programs of different countries indicate reduced efficacy of 2 doses against virological and disease end points. Some recent studies observed the protective effect of single dose of the vaccine against incident and persistent infections of the vaccine targeted HPV types to be similar to 3 doses in spite of immunological inferiority. The sample size, duration of follow-ups and number of events were limited in these studies. Longer follow ups of the less than 3 doses cohorts in the ongoing studies as well as appropriately designed and ethically justifiable randomized studies are needed to establish the protection offered by the alternative schedules at least beyond 10 y of vaccination.
摘要：
世界卫生组织（WHO）根据免疫桥接研究，为15岁以下的女孩推荐了2剂人乳头瘤病毒（HPV）疫苗，该研究表明，青春期女孩的2剂免疫反应不差，而年轻的成年妇女的3剂免疫反应已确定对疾病的功效。构成HPV疫苗的抗原(病毒样颗粒)的生物学性质是引起强烈抗体应答的原因,这可能使第三剂量变得多余。在非随机临床试验中已证明2剂提供的保护与3剂提供的针对疫苗靶向HPV类型的事件和持续感染的保护相当。然而,纳入不同国家人群筛查计划的生态学和嵌套病例对照研究得出的结果表明,2种剂量对病毒学和疾病终点的疗效降低.最近的一些研究观察到单剂量的疫苗对针对HPV类型的疫苗的偶发和持续感染的保护作用类似于3剂量,尽管存在免疫劣性。样本量,在这些研究中,随访时间和事件数量有限.在正在进行的研究中，需要对少于3个剂量的队列进行更长时间的随访，以及适当设计和伦理上合理的随机研究，以建立替代时间表提供的保护，至少超过10年的疫苗接种。
