Mathematically speaking, if 70% of Americans have the vaccine, and the vaccine is 94% effective in preventing new CoVid cases, how does this graph of new CoVid cases make sense?

Source for the 70%: Government.
Source for the 94%: Media.
Source for the new graph: Hospitals.

Has there ever been a time in history when people need to get a vaccine and wear a mask in addition to their vaccine just to go to the store.