Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia.
Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, United Kingdom.
J Infect Dis. 2018 Sep 22;218(suppl_2):S57-S62. doi: 10.1093/infdis/jiy418.
Some 50 years ago, Edgar Hope-Simpson published his hypothesis regarding the interactions between varicella and herpes zoster. As part of this hypothesis, Hope-Simpson postulated that reactivation of varicella zoster virus (VZV) was under immunological control, and that this immunological control could be boosted "endogenously" due to reactivation of latent VZV, and "exogenously" due to exposure to varicella. This hypothesis has important policy implications and remains a source of debate today; namely, does reducing VZV circulation through effective pediatric varicella vaccination programs lead to unintended increases in herpes zoster (HZ) incidence? This article provides 2 very different perspectives on this issue. The first perspective (Rafael Harpaz: Evidence Against an Effect) highlights the empiric experience of the United States, with its population of >300 million, a highly effective national varicella vaccination program lasting >20 years, and with several credible sources of data regarding HZ incidence. The US data have shown an increase in HZ incidence that preceded the availability of varicella vaccination by decades; indeed, HZ rates appear to have plateaued among older adults since varicella vaccination was introduced. Furthermore, HZ rates are not different in states having higher vs lower preschool varicella vaccination rates. The second perspective (Albert J. van Hoek: Evidence for an Effect) cites data that persons with close exposure to children appear to be at lower risk of HZ before universal VZV vaccination, but not so thereafter. Due to historic demographic changes, exogenous boosting could play a role in explaining the observed increase in HZ before varicella vaccination. Thus, it might be difficult to separate declines in exogenous boosting due to demographic changes from those caused by the varicella vaccination program. Additional data will be needed to conclusively rule out an impact of varicella vaccination on HZ.
大约 50 年前，Edgar Hope-Simpson 发表了他关于水痘带状疱疹病毒（varicella zoster virus，VZV）之间相互作用的假说。在这个假说中，Hope-Simpson 假设 VZV 的再激活受免疫控制，这种免疫控制可以由于潜伏的 VZV 的再激活而“内源性”增强，也可以由于接触水痘而“外源性”增强。这个假说具有重要的政策意义，至今仍是争论的焦点；即通过有效的儿科水痘疫苗接种计划减少 VZV 的传播是否会导致带状疱疹（herpes zoster，HZ）发病率的意外增加？本文提供了两种截然不同的观点。第一个观点（Rafael Harpaz：没有效果的证据）强调了美国的经验，美国拥有超过 3 亿人口，有 20 多年历史的高效国家水痘疫苗接种计划，以及关于 HZ 发病率的几个可靠数据源。美国的数据显示，HZ 发病率的增加先于水痘疫苗接种几十年；事实上，自从引入水痘疫苗以来，HZ 发病率在老年人中似乎已经趋于平稳。此外，在水痘疫苗接种率较高和较低的州，HZ 发病率没有差异。第二个观点（Albert J. van Hoek：有效果的证据）引用了这样的数据，即与儿童密切接触的人在普遍接种 VZV 之前似乎患 HZ 的风险较低，但之后就不是这样了。由于历史人口变化，外源性增强可能在解释水痘疫苗接种前 HZ 观察到的增加中发挥作用。因此，由于人口变化而导致的外源性增强的下降可能与由于水痘疫苗接种计划而导致的下降难以区分。需要更多的数据来明确排除水痘疫苗接种对 HZ 的影响。
