Bonanni Paolo, Boccalini Sara, Bechini Angela
Department of Public Health, University of Florence, Viale G.B. Morgagni 48, 50134 Florence, Italy.
Vaccine. 2009 May 29;27 Suppl 1:A46-53. doi: 10.1016/j.vaccine.2008.10.085.
The efficacy and immunogenicity of HPV vaccines has proven excellent in several phase 2 and phase 3 trials involving tens of thousand women. A decrease in antibody titres was observed in follow-up studies of vaccinees, with initial sharp decline reaching a plateau in the longer term. Only few subjects lost their antibodies during the 5-6 years after vaccination. However, no breakthrough disease occurred even in those subjects. The administration of a challenge dose of quadrivalent vaccine at month 60 of follow-up resulted in a strong anamnestic response. The mechanism by which vaccination confers protection and the reasons for continuing vaccine efficacy remain to be elucidated. The same applies to the possibility of inducing an anamnestic response following viral challenge via genital mucosa. Data strongly suggest that both vaccines can have a variable level of cross protection against HPV types genetically and antigenically-closely related to vaccine types. Demonstration of cross protection against combined endpoints (CIN2/3 and AIS) for combined HPV types, and, as a single type, for HPV-31, has been reached for the quadrivalent vaccine, and there is evidence of cross protection against HPV 31 and 45 persistent infections (as single types) for the bivalent vaccine. Assays used for antibody detection were different for the two vaccines, and standardisation of methods for anti-HPV L1 protein detection is presently underway. The possibility to use universally accepted tests for antibody measurement would make comparison between vaccines and among different studies much easier.
在涉及数万名女性的多项2期和3期试验中，HPV疫苗的有效性和免疫原性已得到充分证实。在对疫苗接种者的随访研究中观察到抗体滴度有所下降，最初急剧下降，长期来看趋于平稳。在接种疫苗后的5至6年里，只有少数受试者的抗体消失。然而，即使在这些受试者中也未出现突破性疾病。在随访第60个月时给予一剂四价疫苗激发剂量，引发了强烈的回忆反应。疫苗提供保护的机制以及疫苗持续有效的原因仍有待阐明。通过生殖器黏膜进行病毒激发后诱导回忆反应的可能性也是如此。数据有力地表明，两种疫苗对与疫苗类型在基因和抗原上密切相关的HPV类型都可能具有不同程度地交叉保护作用。四价疫苗已证实对联合HPV类型以及作为单一类型的HPV-31的联合终点（CIN2/3和AIS）具有交叉保护作用，并且有证据表明二价疫苗对HPV 31和45持续感染（作为单一类型）具有交叉保护作用。两种疫苗用于抗体检测的方法不同，目前正在对检测抗HPV L1蛋白的方法进行标准化。使用普遍接受的抗体检测方法将使不同疫苗之间以及不同研究之间的比较更加容易。
