I think it's the Asian idea of taking responsibility. If you get onto a packed train with a runny nose, but are wearing a mask, that's taking responsibility.

In the West, we have a "it's God's Will" idea when things go wrong. But in eastern countries, there's the idea that some party must take responsibility for things to be put right. I think that's why Japan is being so cautious with this shot because with adverse effects, someone will have to be responsible. Voluntary shots make the injectee responsible, and the government payouts covers the government's responsibility for allowing them at all.