What does the snake column in the middle of the health code mean?

The snake column in the middle of the health code is a golden "snake" sign, which reads "COVID-19 vaccination has been completed".

The golden "snake" symbol in the middle of the health code is a walking stick with a snake pattern wrapped around it, which is scientifically called snake stick and used as a medical symbol. There are two kinds of medical marking systems in the world:

One is a double snake stick with wings as the theme;

The other is about a snake wrapped around a stick.

The double snake-winged staff originated from Hermes' wand in Greek mythology. A snake's cane is the main symbol of Asclepius Ashibis, the god of medicine in Roman mythology.