6420Massey University (New Zealand), New Zealand.
University of Southampton (UK), Southampton, United Kingdom.
Eval Rev. 2022 Dec;46(6):709-724. doi: 10.1177/0193841X221085352. Epub 2022 May 30.
Voluminous vaccine campaigns have been used globally, since the COVID-19 pandemic has brought devastating mortality and destructively unprecedented consequences to different aspects of economies. This study aimed to identify how the numbers of new deaths and new cases per million changed after half of the population had been vaccinated. This paper used actual pandemic consequence variables (death and infected rates) together with vaccination uptake rates from 127 countries to shed new light on the efficacy of COVID-19 vaccines. The 50% uptake rate was chosen as the threshold to estimate the real benefits of vaccination campaigns for reducing COVID-19 infection and death cases using the difference-in-differences (DiD) imputation estimator. In addition, a number of control variables, such as government interventions and people's mobility patterns during the pandemic, were also included in the study. The number of new deaths per million significantly decreased after half of the population was vaccinated, but the number of new cases did not change significantly. We found that the effects were more pronounced in Europe and North America than in other continents. Our results remain robust after using other proxies and testing the sensitivity of the vaccinated proportion. We show the causal evidence of significantly lower death rates in countries where half of the population is vaccinated globally. This paper expresses the importance of vaccine campaigns in saving human lives during the COVID-19 pandemic, and its results can be used to communicate the benefits of vaccines and to fight vaccine hesitancy.
全球范围内开展了大规模的疫苗接种活动,因为 COVID-19 大流行给经济的各个方面带来了毁灭性的死亡率和前所未有的破坏。本研究旨在确定在一半人口接种疫苗后,每百万人中新死亡人数和新发病例数的变化情况。本文使用了实际的大流行后果变量(死亡和感染率)以及来自 127 个国家的疫苗接种率,以新的视角研究了 COVID-19 疫苗的功效。选择 50%的接种率作为阈值,使用双重差分(DiD)插补估计量来估计疫苗接种活动在减少 COVID-19 感染和死亡病例方面的实际效益。此外,研究还纳入了一些控制变量,如政府干预措施和大流行期间人们的流动模式。在一半人口接种疫苗后,每百万人中新死亡人数显著下降,但新发病例数没有显著变化。我们发现,在欧洲和北美,这些影响比其他大陆更为明显。我们的结果在使用其他代理和测试接种比例的敏感性后仍然稳健。我们在全球范围内有一半人口接种疫苗的国家中观察到死亡率显著降低的因果证据。本文表达了疫苗接种活动在 COVID-19 大流行期间拯救人类生命的重要性,其结果可用于传播疫苗的益处并对抗疫苗犹豫。