Brisson Marc, Van de Velde Nicolas, De Wals Philippe, Boily Marie-Claude
Département de médecine sociale et préventive, Université Laval, Québec, Que.
CMAJ. 2007 Aug 28;177(5):464-8. doi: 10.1503/cmaj.061709. Epub 2007 Aug 20.
A vaccine against human papillomavirus (HPV) types 6, 11, 16 and 18 is now licensed for use in Canada and many other countries. We sought to estimate the number needed to vaccinate to prevent HPV-related diseases and death.
A cohort model of the natural history of HPV infection was developed. Model simulations were based on 209 different parameter sets that reproduced Canadian HPV type-specific data for infection, cervical intraepithelial neoplasia, cervical cancer and genital warts. The number needed to vaccinate was calculated as the number of women who would need to be vaccinated to prevent an HPV-related event during their lifetime.
Among 12-year-old girls, we estimated that the number needed to vaccinate to prevent an episode of genital warts would be 8 (80% credibility interval [CrI] 5-15) and a case of cervical cancer 324 (80% CrI 195-757). These estimates were based on the assumption that the vaccine procures lifelong protection and that its efficacy is 95%. If vaccine protection is assumed to wane at 3% per year, the predicted number needed to vaccinate would increase to 14 (80% CrI 6-18) and 9080 (80% CrI 1040-does not prevent), respectively. The latter number would be greatly reduced with the addition of a booster dose, to 480 (80% CrI 254-1572).
Our model predictions suggest that vaccination with the currently available HPV vaccine may significantly reduce the incidence of genital warts, cervical intraepithelial neoplasia and cervical cancer. However, the benefits (particularly in terms of cervical cancer reduction) are highly dependent on the duration of vaccine protection, on which evidence is currently limited.
一种针对6、11、16和18型人乳头瘤病毒（HPV）的疫苗现已在加拿大和许多其他国家获得许可使用。我们试图估算为预防HPV相关疾病和死亡所需接种疫苗的人数。
建立了HPV感染自然史的队列模型。模型模拟基于209个不同的参数集，这些参数集再现了加拿大HPV各型别在感染、宫颈上皮内瘤变、宫颈癌和尖锐湿疣方面的特定数据。所需接种人数计算为在其一生中需要接种疫苗以预防HPV相关事件的女性人数。
在12岁女孩中，我们估计预防一例尖锐湿疣所需接种人数为8人（80%可信区间[CrI]5 - 15），预防一例宫颈癌所需接种人数为324人（80% CrI 195 - 757）。这些估计基于疫苗提供终身保护且其效力为95%的假设。如果假设疫苗保护以每年3%的速度减弱，预测所需接种人数将分别增至14人（80% CrI 6 - 18）和9080人（80% CrI 1040 - 无预防效果）。增加一剂加强针后，后者人数将大幅减少至480人（80% CrI 254 - 1572）。
我们的模型预测表明，接种目前可用的HPV疫苗可能会显著降低尖锐湿疣、宫颈上皮内瘤变和宫颈癌的发病率。然而，益处（尤其是在降低宫颈癌方面）高度依赖于疫苗保护的持续时间，而目前关于这方面的证据有限。
