Has Omicron Changed the Evolution of the Pandemic?
Has Omicron Changed the Evolution of the Pandemic?
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DOI：
10.2196/35763
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发表时间：
2022-01-31
影响因子：
8.5
通讯作者：
Post LA
中科院分区：
文献类型：
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作者：
Lundberg AL;Lorenzo-Redondo R;Ozer EA;Hawkins CA;Hultquist JF;Welch SB;Prasad PVV;Oehmke JF;Achenbach CJ;Murphy RL;White JI;Havey RJ;Post LA
SARS-CoV-2病毒的变种对公共卫生的风险不同。Omicron（B.1.1.529）变种于2021年11月11日在博茨瓦纳首次发现，其在全球的传播速度超过了以往任何令人担忧的变种。了解Omicron的可传播性对于制定公共卫生政策至关重要。本研究的目的是比较由Omicron驱动的SARS-CoV-2爆发与由先前关注的变体驱动的SARS-CoV-2爆发的速度和规模。我们分析了几个南部非洲国家的流行趋势与经验证的监测指标。该地区为自然实验提供了理想的环境，因为迄今为止，大多数疫情主要是由一次单一变异驱动的。通过撒哈拉以南非洲国家每日新增感染、总疫苗接种和累计感染的纵向数据集，我们估计了Omicron的出现如何改变了SARS-CoV-2疫情的轨迹。我们使用Arellano-Bond方法来估计动态面板模型的回归系数，其中新感染是昨天和上周感染的函数。我们控制了人群中的疫苗接种和既往感染。为了检验Omicron是否改变了SARS-CoV-2爆发的平均轨迹，我们纳入了Omicron出现和滞后感染的指示变量之间的相互作用。本研究中观察到的Omicron爆发在首次检测后5-10天内达到爆发阈值，而其他令人关注的变体至少需要14天，最多可达35天。Omicron的爆发也达到了新病例的高峰，大约是先前令人担忧的变异的1.5-2倍。动态面板回归估计证实Omicron在病毒传播方面产生了统计学显著变化。Omicron的可传播性明显高于先前关注的变体。在人口一级，奥密克隆爆发的速度更快，规模更大，尽管接种疫苗和先前感染的人数大幅增加，否则会降低对新感染的易感性。除非公共卫生政策得到实质性改变，否则其他国家的Omicron疫情很可能在几乎没有预警的情况下发生。
Variants of the SARS-CoV-2 virus carry differential risks to public health. The Omicron (B.1.1.529) variant, first identified in Botswana on November 11, 2021, has spread globally faster than any previous variant of concern. Understanding the transmissibility of Omicron is vital in the development of public health policy. The aim of this study is to compare SARS-CoV-2 outbreaks driven by Omicron to those driven by prior variants of concern in terms of both the speed and magnitude of an outbreak. We analyzed trends in outbreaks by variant of concern with validated surveillance metrics in several southern African countries. The region offers an ideal setting for a natural experiment given that most outbreaks thus far have been driven primarily by a single variant at a time. With a daily longitudinal data set of new infections, total vaccinations, and cumulative infections in countries in sub-Saharan Africa, we estimated how the emergence of Omicron has altered the trajectory of SARS-CoV-2 outbreaks. We used the Arellano-Bond method to estimate regression coefficients from a dynamic panel model, in which new infections are a function of infections yesterday and last week. We controlled for vaccinations and prior infections in the population. To test whether Omicron has changed the average trajectory of a SARS-CoV-2 outbreak, we included an interaction between an indicator variable for the emergence of Omicron and lagged infections. The observed Omicron outbreaks in this study reach the outbreak threshold within 5-10 days after first detection, whereas other variants of concern have taken at least 14 days and up to as many as 35 days. The Omicron outbreaks also reach peak rates of new cases that are roughly 1.5-2 times those of prior variants of concern. Dynamic panel regression estimates confirm Omicron has created a statistically significant shift in viral spread. The transmissibility of Omicron is markedly higher than prior variants of concern. At the population level, the Omicron outbreaks occurred more quickly and with larger magnitude, despite substantial increases in vaccinations and prior infections, which should have otherwise reduced susceptibility to new infections. Unless public health policies are substantially altered, Omicron outbreaks in other countries are likely to occur with little warning.