You Do Need power plug adapter while traveling from Vatican City to Sierra Leone.

Here is Why You Need An Adapter

The outlet and plug type used in Sierra Leone are D and G and in Vatican City are C, F and L. This is how they look like.

Vatican City

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

Type C

Type F

Type L

Sierra Leone

In Sierra Leone, outlets of type D and G are in use.

Type D

Type G