The Vampire's Assistant (2009)

AKA: Cirque du Freak
Genre: Action | Adventure | Comedy | Fantasy | Horror | Thriller
Tagline: Meet Darren. He's sixteen going on immortal.
Starring: Chris Massoglia, John C. Reilly, Salma Hayek, and Josh Hutcherson

Plot: A young boy named Darren Shan meets a mysterious man at a freak show who turns out to be a Vampire. After a series of events Darren must leave his normal life and go on the road with the Cirque Du Freak and become a Vampire.

http://www.imdb.com/title/tt0450405/
http://en.wikipedia.org/wiki/Cirque_du_Freak:_The_Vampire%27s_Assistant