translation.en: Luckily, the genetic testing proved that, in fact, this strand came north, because, had it come from the south, it would have had a much wider impact in terms of transmission.
translation.zh: 所幸的是，基因测试证明了 这个病毒株是从北部来的， 因为如果是从南方来的， 那么它的传播范围会更广。