Le Rutte Epke A, Shattock Andrew J, Chitnis Nakul, Kelly Sherrie L, Penny Melissa A
Swiss Tropical and Public Health Institute, Allschwil, Switzerland.
University of Basel, Basel, Switzerland.
Commun Med (Lond). 2022 Jul 25;2:93. doi: 10.1038/s43856-022-00154-z. eCollection 2022.
SARS-CoV-2 variants of concern, such as Omicron (B.1.1.529), continue to emerge. Assessing the impact of their potential viral properties on the probability of future transmission dominance and public health burden is fundamental in guiding ongoing COVID-19 control strategies.
With an individual-based transmission model, OpenCOVID, we simulated three viral properties; infectivity, severity, and immune-evading ability, all relative to the Delta variant, to identify thresholds for Omicron's or any emerging VOC's potential future dominance, impact on public health, and risk to health systems. We further identify for which combinations of viral properties current interventions would be sufficient to control transmission.
We show that, with first-generation SARS-CoV-2 vaccines and limited physical distancing in place, a VOC's potential future dominance is primarily driven by its infectivity, which does not always lead to an increased public health burden. However, we also show that highly immune-evading variants that become dominant, even in the case of reduced variant severity, would likely require alternative measures to avoid strain on health systems, such as strengthened physical distancing measures, novel treatments, and second-generation vaccines. Expanded vaccination, that includes a booster dose for adults and child vaccination strategies, is projected to have the biggest public health benefit for a highly infective, highly severe VOC with low immune-evading capacity.
These findings provide quantitative guidance to decision-makers at a critical time while Omicron's properties are being assessed and preparedness for emerging VOCs is eminent. We emphasise the importance of both genomic and population epidemiological surveillance.
值得关注的新冠病毒变异株，如奥密克戎（B.1.1.529），仍在不断出现。评估其潜在病毒特性对未来传播优势概率和公共卫生负担的影响，对于指导当前的新冠疫情防控策略至关重要。
我们使用基于个体的传播模型OpenCOVID，模拟了三种病毒特性；传染性、严重性和免疫逃逸能力，所有这些均相对于德尔塔变异株，以确定奥密克戎或任何新出现的变异株未来潜在优势、对公共卫生的影响以及对卫生系统的风险阈值。我们还确定了对于哪些病毒特性组合，当前的干预措施足以控制传播。
我们表明，在第一代新冠疫苗接种且保持有限的物理距离措施的情况下，一种变异株未来的潜在优势主要由其传染性驱动，而这并不总是导致公共卫生负担增加。然而，我们也表明，即使变异株严重性降低，但成为优势毒株的高免疫逃逸变异株可能需要采取替代措施以避免给卫生系统造成压力，如加强物理距离措施、新型治疗方法和第二代疫苗。预计扩大疫苗接种，包括为成年人接种加强针以及儿童疫苗接种策略，对于具有高传染性、高严重性且低免疫逃逸能力的变异株将带来最大的公共卫生益处。
在评估奥密克戎特性以及为新出现的变异株做好准备的关键时期，这些发现为决策者提供了定量指导。我们强调基因组监测和人群流行病学监测的重要性。
