Vaccination remains a critical element in the eventual solution to the COVID-19 public health crisis. Many vaccines are already being mass produced and supplied in many countries. However, the COVID-19 vaccination programme will be the biggest in history. Reaching herd immunity will require an unprecedented mass immunisation campaign that will take several months and millions of dollars.

Using different network models, COVID-19 pandemic dynamics of different countries can be recapitulated such as in Italy. Stochastic computational simulations highlight that peak epidemic sizes in a population strongly depend on the network structure. Assuming a vaccine efficacy of at least $80\%$ in a mass vaccination program, at least $70\%$ of a given population should be vaccinated to obtain herd immunity, independently of the network structure. If the vaccine efficacy reports lower levels of efficacy in practice, then the coverage of vaccination would be needed to be even higher. Simulations suggest that the “Ring of Vaccination” strategy, vaccinating susceptible contact and contact of contacts, would prevent new waves of COVID −19 meanwhile a high percent of the population is vaccinated.

疫苗接种仍然是最终解决 COVID-19 公共卫生危机的关键因素。许多疫苗已经在许多国家大规模生产和供应。然而，COVID-19 疫苗接种计划将是历史上规模最大的。实现群体免疫将需要一场前所未有的大规模免疫运动，这将需要数月时间和数百万美元。

使用不同的网络模型，可以概括不同国家的 COVID-19 大流行动态，例如在意大利。随机计算模拟强调，人口中流行病的峰值规模在很大程度上取决于网络结构。假设疫苗效力至少为$80\%$在大规模疫苗接种计划中，至少$70\%$应该为给定人群接种疫苗以获得群体免疫，而与网络结构无关。如果疫苗功效在实践中报告的功效水平较低，那么疫苗接种的覆盖率将需要更高。模拟表明，“疫苗接种环”策略，即为易感接触者和接触者的接触者接种疫苗，将防止新一波 COVID -19，同时有很高比例的人口接种疫苗。