msn/mph

hello my fellow nurses!

I have been nurse for a year and a half in medical surgical unit. I am so confused on pursing my further education as a NP or MSN/MPH since i kindda want to work for WHO! I hear a lot of buzz about NP but hardly anything about MSN/MPH. I would like to hear from some people who have done MSN/MPH and are successful in those fields!
PLZ help me!
a degree does not make you successful. So in the most positive way possible, I'm saying, you will do fine at whatever you choose, as long as your heart is in it.

Have you investigated what kind of nursing positions WHO has? What kind of credentials the nurses they hire have? That would be important to know, I would think, if working for WHO is one of your goals.