You Do Need power plug adapter while traveling from Central African Republic to Vietnam.

Here is Why You Need An Adapter

The outlet and plug type used in Vietnam are A, B and C and in Central African Republic are C and E. This is how they look like.

Central African Republic

In Central African Republic, outlets of type C and E are in use.

Type C

Type E

Vietnam

In Vietnam, outlets of type A, B and C are in use.

Type A

Type B

Type C