The new coronavirus was circulating in Italy since September 2019, a study by the National Cancer Institute (INT) of the Italian city of Milan
The new coronavirus was circulating in Italy since September 2019, a study by the National Cancer Institute of the Italian city of Milan shows.
www.cnbc.com
意大利某研究组织对959人的血液样本检测后发现,其中部分在2019年9月份采集的血液里已经又covid 19的抗体。
这怎么解释?