The original vampire hunter from the book Bram Strokers Dracula (the orginal dracula book published back in the day that started all the dracula mythology) was named something Van Helsing (can't remember the first name). This new movie was suppose to be another version of the original story, starring the same Van Helsing. The movie company couldn't/didn't want to pay for the rights to the name so they named H.J. Van Helsing with a different first name and made him the son of the original vampire hunter. So basically any spin off of the original Dracula story is gonna use the name Va Helsing just as they would use the name Dracula. And by the way I've never read the original book or seen the movie, I just somehow know all this from reading magazine articles.