China’s vaccine rollout is complicated
China's goal is to inoculate about 70% of its population. That's nearly a billion people. And it's got a big challenge. It hasn't been able to test its two vaccines in its own country. That's because the infection rates are so low in China, they can't perform proper clinical trials there. As The World’s Rebecca Kanthor reports, China's success in controlling the virus is now making the vaccination process considerably more complicated.