留存血样档案可以追溯新冠病毒，美国CDC查了一下红十字去年12月下半月西海岸血样与东海岸1月上旬血样7389，其中西海岸发现39个带新冠抗体，东海岸发现67个带新冠抗体。（为何没测更早的？估计今后会测。）
估计今后全球会有更多的血样测试追溯，新冠起始与传播情况会逐步有清晰结论。
“ COVID-19 was silently infecting Americans before first cases emerged in Wuhan: CDC study
Coronavirus was present in the U.S. weeks earlier than scientists and public health officials previously thought, raising questions about the pandemic origin”
https://www.google.ca/amp/s/national...334cb431f/amp/