摘要
Since the end of 2021,the world has been grappling with a series of coronavirus 2019(COVID-19)outbreaks caused by the highly transmissible Omicron variant.Though the Omicron variant has a fatality rate that is lower than other variants and high vaccine coverage,more countries have lifted their non-pharmaceutical interventions(NPIs)and tried to combine natural infection and vaccine immunity to achieve herd immunity so as to coexist with the virus.
基金
supported by National Key Research and Development Program of China(2021YFC2301604)
Chinese Postdoctoral Science Foundation(2020T130020ZX)
the Science and Technology Program of Guangzhou(202102021285)
the Emergency Grants for Prevention and Control of SARS-CoV-2 of Guangdong Province(2022A1111090004).