Adriaensen Wim, Oostvogels Selien, Levy Yves, Leigh Bailah, Kavunga-Membo Hugo, Watson-Jones Deborah
Clinical Immunology Unit, Department of Clinical Sciences, Institute of Tropical Medicine Antwerp, Antwerp, Belgium.
Clinical Immunology Unit, Department of Clinical Sciences, Institute of Tropical Medicine Antwerp, Antwerp, Belgium.
Lancet Infect Dis. 2024 Oct;24(10):e647-e653. doi: 10.1016/S1473-3099(24)00210-X. Epub 2024 May 8.
With two endorsed and prophylactic vaccines against Zaire ebolavirus (referred to hereafter as EBOV), the number of individuals vaccinated against EBOV worldwide is estimated to range between 500 000 and 1 000 000 individuals, increasing with every renewed EBOV threat and vaccination campaign. Therefore, re-exposure of previously vaccinated health-care workers, and possibly community members, could become more frequent. In the absence of long-term data on vaccine efficacy and duration of protection, we urgently need to understand revaccination strategies that could maximise the level of protection. In this Personal View, we highlight the scarcity of available evidence to guide revaccination recommendations for the accumulating groups of previously vaccinated communities or front-line health-care workers that could be redeployed or re-exposed in the next EBOV outbreak(s). This evidence base is crucial to identify optimal target populations and the frequency of booster doses, and guide vaccine interchangeability (especially in settings with limited or unpredictable vaccine supplies), while preventing vaccine mistrust, equity concerns, and exclusion of vulnerable populations. We discuss five priority gaps (to whom, when, and how frequently, to provide booster doses; long-term correlates and thresholds of protection; the effect of vector-directed immunity and viral variant protection; comparative research in mix-and-match schedules; and implementation concerns) that should be urgently tackled to adapt the initial EBOV prophylactic vaccination strategies considering potential booster dose vaccinations.
有两种已获认可的针对扎伊尔埃博拉病毒（以下简称埃博拉病毒）的预防性疫苗，全球接种埃博拉病毒疫苗的人数估计在50万至100万人之间，且随着每次新出现的埃博拉病毒威胁和疫苗接种活动而增加。因此，之前接种过疫苗的医护人员以及可能的社区成员再次接触病毒的情况可能会更加频繁。由于缺乏关于疫苗效力和保护持续时间的长期数据，我们迫切需要了解能够使保护水平最大化的再接种策略。在这篇个人观点文章中，我们强调了现有证据的匮乏，这些证据可用于指导对越来越多的已接种疫苗社区或一线医护人员群体的再接种建议，这些人员可能会在未来的埃博拉病毒疫情中被重新部署或再次接触病毒。这一证据基础对于确定最佳目标人群和加强剂量的频率、指导疫苗的互换性（特别是在疫苗供应有限或不可预测的情况下）、防止疫苗不信任、公平性问题以及排除弱势群体至关重要。我们讨论了五个优先差距（向谁、何时以及多频繁地提供加强剂量；长期的保护相关性和阈值；载体介导免疫和病毒变异体保护的影响；混合搭配接种方案的比较研究；以及实施方面的问题），为了适应考虑潜在加强剂量接种的初始埃博拉病毒预防性疫苗接种策略，这些差距亟待解决。
