Table_1_Evolving trend change during the COVID-19 pandemic.DOCX

Coronavirus disease (COVID-19) has caused unimaginable damage to public health and socio-economic structures worldwide; thus, an epidemiological depiction of the global evolving trends of this disease is necessary. As of March 31, 2022, the number of cases increased gradually over the four waves of the COVID-19 pandemic, indicating the need for continuous countermeasures. The highest total cases per million and total deaths per million were observed in Europe (240,656.542) and South America (2,912.229), despite these developed countries having higher vaccination rates than other continents, such as Africa. In contrast, the lowest of the above two indices were found in undeveloped African countries, which had the lowest number of vaccinations. These data indicate that the COVID-19 pandemic is positively related to the socio-economic development level; meanwhile, the data suggest that the vaccine currently used in these continents cannot completely prevent the spread of COVID-19. Thus, rethinking the feasibility of a single vaccine to control the disease is needed. Although the number of cases in the fourth wave increased exponentially compared to those of the first wave, ~43.1% of deaths were observed during the first wave. This was not only closely linked to multiple factors, including the inadequate preparation for the initial response to the COVID-19 pandemic, the gradual reduction in the severity of additional variants, and the protection conferred by prior infection and/or vaccination, but this also indicated the change in the main driving dynamic in the fourth wave. Moreover, at least 12 variants were observed globally, showing a clear spatiotemporal profile, which provides the best explanation for the presence of the four waves of the pandemic. Furthermore, there was a clear shift in the trend from multiple variants driving the spread of disease in the early stage of the pandemic to a single Omicron lineage predominating in the fourth wave. These data suggest that the Omicron variant has an advantage in transmissibility over other contemporary co-circulating variants, demonstrating that monitoring new variants is key to reducing further spread. We recommend that public health measures, along with vaccination and testing, are continually implemented to stop the COVID-19 pandemic.

新冠病毒病（COVID-19）对全球公共卫生和社会经济结构造成了难以想象的破坏；因此，对该疾病全球演变趋势的流行病学研究是必要的。截至2022年3月31日，病例数在COVID-19大流行的四波中逐渐增加，这表明需要持续采取对策。尽管这些发达国家相较于其他大洲如非洲，疫苗接种率较高，但每百万人口中的最高总病例数和总死亡数分别出现在欧洲（240,656.542）和南美洲（2,912.229）。相反，上述两项指数的最低值出现在疫苗接种率最低的未发达国家。这些数据表明，COVID-19大流行与社会经济发展水平呈正相关；同时，数据也表明，这些大洲目前使用的疫苗无法完全阻止COVID-19的传播。因此，重新思考单一疫苗控制疾病可行性的必要性变得迫切。尽管第四波病例数与第一波相比呈指数级增长，但观察到~43.1%的死亡病例发生在第一波。这不仅与多个因素密切相关，包括对COVID-19大流行初期应对准备不足、额外变种的严重程度逐渐降低以及先前感染和/或疫苗接种提供的保护，而且还表明第四波的主导动力发生了变化。此外，全球观察到了至少12个变种，显示出明显的时空特征，这为解释大流行的四波提供了最合理的解释。进一步地，从大流行早期由多个变种驱动疾病传播的趋势，到第四波中Omicron谱系占主导地位，这一趋势发生了明显转变。这些数据表明，Omicron变种在传播性方面相较于其他同期共循环的变种具有优势，这证明了监测新变种是减少进一步传播的关键。我们建议，公共健康措施，包括疫苗接种和检测，应持续实施，以遏制COVID-19大流行。