Wang Yan, Sun Kaiyuan, Feng Zhaomin, Yi Lan, Wu Yanpeng, Liu Hengcong, Wang Quanyi, Ajelli Marco, Viboud Cécile, Yu Hongjie
School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China.
Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
medRxiv. 2022 Jun 6:2022.05.07.22274792. doi: 10.1101/2022.05.07.22274792.
We developed a spatially structured, fully stochastic, individual-based SARS-CoV-2 transmission model to evaluate the feasibility of sustaining SARS-CoV-2 local containment in mainland China considering currently dominant Omicron variants, China's current immunization level, and non-pharmaceutical interventions (NPIs). We also built a statistical model to estimate the overall disease burden under various hypothetical mitigation scenarios. We found that due to high transmissibility, neither Omicron BA.1 or BA.2 could be contained by China's pre-Omicron NPI strategies which were successful prior to the emergence of the Omicron variants. However, increased intervention intensity, such as enhanced population mobility restrictions and multi-round mass testing, could lead to containment success. We estimated that an acute Omicron epidemic wave in mainland China would result in significant number of deaths if China were to reopen under current vaccine coverage with no antiviral uptake, while increasing vaccination coverage and antiviral uptake could substantially reduce the disease burden. As China's current vaccination has yet to reach high coverage in older populations, NPIs remain essential tools to maintain low levels of infection while building up protective population immunity, ensuring a smooth transition out of the pandemic phase while minimizing the overall disease burden.
我们构建了一个空间结构化、完全随机、基于个体的新冠病毒传播模型,以评估在中国内地维持新冠病毒局部控制的可行性,其中考虑了当前占主导的奥密克戎变种、中国目前的免疫水平以及非药物干预措施(NPIs)。我们还建立了一个统计模型,以估计各种假设的缓解情景下的总体疾病负担。我们发现,由于奥密克戎的高传播性,中国在奥密克戎变种出现之前成功实施的、针对奥密克戎出现前情况的非药物干预策略,无法控制奥密克戎BA.1或BA.2毒株。然而,提高干预强度,如加强人口流动限制和多轮大规模检测,可能会导致控制成功。我们估计,如果中国在目前的疫苗接种覆盖率且无抗病毒药物使用的情况下重新开放,中国大陆的奥密克戎急性疫情波将导致大量死亡,而提高疫苗接种覆盖率和抗病毒药物使用率可以大幅减轻疾病负担。由于中国目前在老年人群中的疫苗接种尚未达到高覆盖率,非药物干预措施仍然是维持低感染水平的重要工具,同时建立人群保护性免疫,确保平稳过渡到疫情结束阶段,同时将总体疾病负担降至最低。