摘要
Summary What is already known about this topic?Though coronavirus disease 2019(COVID-19)has largely been controlled in China,several outbreaks of COVID-19 have occurred from importation of cases or of suspected virus-contaminated products.Though several outbreaks have been traced to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)isolated on the outer packaging of cold chain products,live virus has not been obtained.
基金
The SARS-CoV-2 emergency special project of the Chinese Government and National Key Research and Development Project(Project No.2021YFC0863000)
National Natural Science Foundation of China(No.72042012)
the National Key Technology R&D Program of China(Project No.2017ZX10104001,2018ZX10713002,2018ZX10713001-003,and 2018ZX10711001).
