Vanillin is the name of the chemical component that's mainly responsible for the vanilla taste in vanilla pods. It used to be made with a simple process from wood pulp obtained from the paper industry which was also very efficient and innocent. They mainly switched over to GMO yeasts in bioreactors that produce vanillin in large quantities. As far as I know this vanillin is pure and clean and shouldn't pose any health danger compared to vanilla pods. However it's not exactly a vanilla pod in taste because vanillin is just one of its many, many chemical components and thus this vanillin misses the subtle real vanilla flavouring - but it does get pretty close.