Makhoul Monia, Chemaitelly Hiam, Ayoub Houssein H, Seedat Shaheen, Abu-Raddad Laith J
Infectious Disease Epidemiology Group, Weill Cornell Medicine-Qatar, Cornell University, Qatar Foundation-Education City, Doha 24144, Qatar.
World Health Organization Collaborating Centre for Disease Epidemiology Analytics on HIV/AIDS, Sexually Transmitted Infections, and Viral Hepatitis, Weill Cornell Medicine-Qatar, Cornell University, Qatar Foundation-Education City, Doha 24144, Qatar.
Vaccines (Basel). 2021 Mar 5;9(3):223. doi: 10.3390/vaccines9030223.
This study forecasts Coronavirus Disease 2019 (COVID-19) vaccination impact in two countries at different epidemic phases, the United States (US) and China. We assessed the impact of both a vaccine that prevents infection ( of 95%) and a vaccine that prevents only disease ( of 95%) through mathematical modeling. For of 95% and gradual easing of restrictions, vaccination in the US reduced the peak incidence of infection, disease, and death by >55% and cumulative incidence by >32% and in China by >77% and >65%, respectively. Nearly three vaccinations were needed to avert one infection in the US, but only one was needed in China. For of 95%, vaccination benefits were half those for of 95%. In both countries, impact of vaccination was substantially enhanced with rapid scale-up, vaccine coverage >50%, and slower or no easing of restrictions, particularly in the US. COVID-19 vaccination can flatten, delay, and/or prevent future epidemic waves. However, vaccine impact is destined to be heterogeneous across countries because of an underlying "epidemiologic inequity" that reduces benefits for countries already at high incidence, such as the US. Despite 95% efficacy, actual vaccine impact could be meager in such countries if vaccine scale-up is slow, acceptance is poor, or restrictions are eased prematurely.
本研究预测了2019冠状病毒病（COVID-19）疫苗接种在两个处于不同疫情阶段的国家——美国和中国的影响。我们通过数学建模评估了一种预防感染（有效率95%）的疫苗和一种仅预防疾病（有效率95%）的疫苗的影响。对于有效率95%且限制措施逐步放宽的情况，美国的疫苗接种使感染、疾病和死亡的峰值发病率降低了55%以上，累计发病率降低了32%以上，而在中国分别降低了77%以上和65%以上。在美国，平均需要接种近三针疫苗才能避免一次感染，但在中国只需一针。对于有效率95%的情况而言，疫苗接种的益处仅为有效率95%情况的一半。在这两个国家，通过快速扩大接种规模、疫苗接种覆盖率超过50%以及减缓或不放宽限制措施，疫苗接种的影响得到了显著增强，在美国尤其如此。COVID-19疫苗接种可以使未来的疫情波趋于平缓、延迟和/或预防。然而，由于潜在的“流行病学不平等”，疫苗影响在各国之间注定存在差异，这种不平等降低了对已经处于高发病率的国家（如美国）的益处。尽管疫苗有效率为95%，但如果疫苗接种规模扩大缓慢、接受度低或过早放宽限制措施，在这些国家实际的疫苗影响可能微乎其微。
