Are you really saying you knew nothing about AIDS or the Landmines until Diana had her picture in the magazines? It is perhaps an American 'thing', to only listen to what celebs tell you. Angelina in particular is a very poor example
Angelina Jolie Facing Legal Woes Over Cambodian Exploitations - Associated Content
Unicef existed before the celebs were involved and some seem to do it for publicity reasons. Do you immediately think AIDS whenever you see Diana or Elton, no of course not.
Vivienne Parry should realise that AIDS is now a normal part of life for some, it is no longer new and frightening, although perhaps it should be. Very many people work hard to raise money for research, they always have and it didn't all begin and end with Diana.