You Do Need power plug adapter while traveling from American Samoa to Vatican City.

Here is Why You Need An Adapter

The outlet and plug type used in Vatican City are C, F and L and in American Samoa are A, B, F and I. This is how they look like.

American Samoa

In American Samoa, outlets of type A, B, F and I are in use.

Type A

Type B

Type F

Type I

Vatican City

In Vatican City, outlets of type C, F and L are in use.

Type C

Type F

Type L