<P> Much of Elena 's story revolves around her relationships with vampires Stefan Salvatore and his older brother , Damon . It is revealed that Elena is a Petrova Doppelgänger , which is thus responsible for her being identical to her ancestor , Katherine Pierce ( née Katerina Petrova ) . This also has the implication of making her a supernatural creature . Dobrev portrayed the `` conniving '' Katherine as well , who is opposite of Elena . The actress stated that it has been a challenge distinguishing the two , and enjoys playing them both . In the television series 's fourth season , Elena becomes a vampire and deals with the struggles that come with her change . She took the cure and became human again towards the end of the sixth season . In the finale of the sixth season , Kai linked Elena to Bonnie 's life by magic . Elena will only wake up when Bonnie dies in around 60 years . She was locked inside the Salvatore tomb , which was changed in the seventh season , and was relocated in Brooklyn , New York . In late 2016 , when it was announced that the eighth season would be the final season , Dobrev was in talks about returning to the television series to reprise her role in the final episode . After much speculation . Dobrev 's return was confirmed on January 26 , 2017 , via an Instagram post . Dobrev appeared in the final episode of the show as both Elena and her evil doppelgänger Katherine Pierce . </P>
when does elena turn into a vampire in the tv series
fourth season