It is always best to have the yellow fever innoculation if you are travelling to and from Africa. If you are from Australia and you travel to Africa you are not allowed back in to Australia without your yellow fever certificate. It dosen't hurt to have the innoculation, once you have it you will be fine to travel wherever and not have to worry about it.
While travelling in Africa when i got to some boarders i was not allowed in until i had shown my yellow fever certificate.
So best thing i can suggest is to just have the injection then you wont have to worry when you are travelling. about 10 years ago