Chinese Covid-19 vaccines offer relatively low levels of protection compared with some of their foreign rivals. Here is why China is joining other countries in considering mixing and matching vaccines as a key to overcoming multiple vaccination challenges at once. Illustration: Ksenia Shaikhutdinova More from the Wall Street Journal: Visit WSJ.com: http://www.wsj.com/ Visit the WSJ Video Center: https://wsj.com/video On Facebook: https://www.facebook.com/pg/wsj/videos/ On Twitter: https://twitter.com/WSJ On Snapchat: https://on.wsj.com/2ratjSM #WSJ #Chinavaccine #Chinesevaccine