Accidental. If it was planned and they had the vaccine in place for their own citizens, they wouldn’t be freaking out like they are. It wouldnt have started in China ( much less 20 miles from a level 4 Bioresearch center). Another poster mentioned multiple scenarios where cutting a corner or two in building the lab could allow accidental transfer.
“...vaccine in place for their own citizens,...”
Well, I’m not sure the ChiComs care too much about their own slaves... Look at what they did to the Tianeman Square people.
In their mind, what’s a few thousand lives versus the “good of the Party”.
Maybe you’re right, though... I just put nothing past that government, ever.