Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT 06520-8034, USA.
J Infect Dis. 2012 Oct;206(8):1291-8. doi: 10.1093/infdis/jis494. Epub 2012 Aug 7.
The degree of cross-immunity between human papillomavirus (HPV) types is fundamental both to the epidemiological dynamics of HPV and to the impact of HPV vaccination. Epidemiological data on HPV infections has been repeatedly interpreted as inconsistent with cross-immunity.
We reevaluate the epidemiological data using a model to determine the odds ratios of multiple to single infections expected in the presence or absence of cross-immunity. We simulate a virtual longitudinal survey to determine the effect cross-immunity has on the prevalence of multiple infections. We calibrate our model to epidemiological data and estimate the extent of type replacement following vaccination against specific HPV types.
We find that cross-immunity can produce odds ratios of infection comparable with epidemiological observations. We show that the sample sizes underlying existing surveys have been insufficient to identify even intense cross-immunity. We also find that the removal of HPV type 16, type 18, and types 6 and 11 would increase the prevalence of nontargeted types by 50%, 29%, and 183%, respectively.
Cross-immunity between HPV types is consistent with epidemiological data, contrary to previous interpretations. Cross-immunity may cause significant type replacement following vaccination, and therefore should be considered in future vaccine studies and epidemiological models.
人乳头瘤病毒（HPV）型之间的交叉免疫程度对于 HPV 的流行病学动态和 HPV 疫苗接种的影响至关重要。HPV 感染的流行病学数据被反复解释为与交叉免疫不一致。
我们使用模型重新评估流行病学数据，以确定在存在或不存在交叉免疫的情况下，多重感染与单一感染的优势比。我们模拟一个虚拟的纵向调查，以确定交叉免疫对多重感染的流行程度的影响。我们将我们的模型校准到流行病学数据，并估计针对特定 HPV 型接种疫苗后类型替代的程度。
我们发现，交叉免疫可以产生与流行病学观察相当的感染优势比。我们表明，现有调查的样本量不足以确定即使是强烈的交叉免疫。我们还发现，HPV 型 16、18 和 6 型和 11 型的消除将分别使非靶向型的流行率增加 50%、29%和 183%。
HPV 型之间的交叉免疫与流行病学数据一致，与之前的解释相反。交叉免疫可能会在接种疫苗后导致显著的类型替代，因此应在未来的疫苗研究和流行病学模型中加以考虑。
