Department of Statistics, Sapienza University of Rome, Rome, Italy.
Center for Information Technology, Bruno Kessler Foundation, Trento, Italy; TrentoRise, Trento, Italy.
Vaccine. 2018 Feb 14;36(8):1116-1125. doi: 10.1016/j.vaccine.2018.01.038. Epub 2018 Jan 20.
Adoption of varicella immunization in Europe is limited due to a predicted increase in the incidence of herpes zoster (HZ) resulting from a removal of exogenous boosting by varicella vaccination. Most available assessments of immunization strategies only considered universal varicella vaccination (alone or in combination with HZ by the live vaccine). The development of a new subunit recombinant zoster vaccine may provide new perspectives of HZ control.
We used a mathematical model for VZV in Norway based on the progressive immunity formulation of exogenous boosting. We evaluated a complete range of alternative immunization options against varicella and HZ including both universal and targeted varicella vaccination, either alone or with zoster immunization, and zoster immunization alone. We considered all values of the boosting intensity consistent with the Norwegian HZ incidence and compared the performance of the currently available live vaccine vs. a new recombinant vaccine.
Universal varicella vaccination alone resulted in a marked increase in the incidence of HZ under all scenarios considered. Even under the most favorable hypotheses on the magnitude of the boosting intensity, this increase could be mitigated only by a parallel HZ immunization with a recombinant vaccine, assuming a long duration of protection. Targeted varicella immunization of adolescents resulted in a modest increase in the HZ incidence which could be counterbalanced by both the live and, especially, the recombinant vaccine.
Given current knowledge on HZ pathogenesis and exogenous boosting, targeted varicella vaccination of adolescents was the only strategy that was not predicted to impact the epidemiology of HZ, and therefore it may represent a suitable alternative to universal vaccination. These results are aimed to support vaccine policy decisions in Norway and other countries with a similar VZV epidemiology.
由于水痘疫苗接种消除了外源性增强作用，预计欧洲的水痘免疫接种率会增加，导致带状疱疹（HZ）发病率上升，因此欧洲对水痘免疫接种的采用受到限制。大多数现有的免疫接种策略评估仅考虑了普遍接种水痘疫苗（单独或与活疫苗的 HZ 联合接种）。新的亚单位重组带状疱疹疫苗的开发可能为 HZ 控制提供新的视角。
我们使用了基于外源性增强渐进免疫配方的挪威 VZV 数学模型。我们评估了针对水痘和 HZ 的一系列替代免疫接种方案，包括普遍和有针对性的水痘接种，单独或与带状疱疹免疫接种，以及单独的带状疱疹免疫接种。我们考虑了与挪威 HZ 发病率一致的所有增强强度值，并比较了现有活疫苗与新重组疫苗的性能。
单独普遍接种水痘疫苗会导致在所有考虑的情况下 HZ 发病率显著增加。即使在增强强度的假设最有利的情况下，只有通过平行的重组疫苗进行 HZ 免疫接种，假设保护期长，才能减轻这种增加。对青少年进行有针对性的水痘免疫接种会导致 HZ 发病率适度增加，但这可以通过活疫苗和特别是重组疫苗来平衡。
鉴于目前对 HZ 发病机制和外源性增强的认识，对青少年进行有针对性的水痘疫苗接种是唯一不会预测到 HZ 流行病学的策略，因此它可能是普遍接种的替代方案。这些结果旨在支持挪威和其他具有类似 VZV 流行病学的国家的疫苗政策决策。
