Scientists who track coronavirus mutations are closely monitoring an uptick in cases of an Omicron sub-variant named BA.2, just as countries were beginning to hope the worst of the latest wave of Covid-19 infections had passed.
在各国开始希望最新一波新冠病毒感染的最糟糕时期已经过去之际，追踪新冠病毒突变的科学家正在密切监测一种名为BA.2的奥密克戎(Omicron)亚变体病例的增加。
您已阅读3%（306字），剩余97%（9050字）包含更多重要信息，订阅以继续探索完整内容，并享受更多专属服务。