摘要
Almost 3 years after the outbreak of the novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)responsible for the coronavirus disease 2019(COVID-19)that has caused more than 6 million deaths worldwide,1the pandemic persists and hampers our daily lives.There are at least 2 main reasons explaining why we still struggle to terminate this pandemic.First,novel variants of concern of SARS-CoV-2unceasingly emerge despite almost 12 billion doses of vaccinebeing administered to date.
