China’s homegrown COVID vaccines were once crucial — but they're not as effective against omicron as mRNA jabs.

What's more, with with local cases near zero for the better part of the pandemic, most Chinese have no natural immunity. That could spell disaster for Beijing as omicron surges.

Yanzhong Huang, senior fellow for global health at the Council on Foreign Relations, warns that the highly transmissible new variant will make zero COVID harder and harder to sustain.