Around 1918 the spanish influenza hit and Edward got it too. Carlisle was treating paitents with the disease, and an ill woman asked Carlisle to save her dieing son edward so Carlisle changed Edward into a Vampire.
Well he had to be he IS a vampire
A disease called Spanish Influenza.
Edward was changed by Carlisle Cullen.
He got bit, by a vampire.
influenza
Green
Edward.
Spanis Influenza
Edward pretends to be 17 in the twilight movies as he got changed by carlisle into a vampire when he was 17 because he was dieing of spanish influenza and it was his mothers dieing wish for that to happen.
Edward Cullen is a Vampire because Carlisle Cullen changed edward because Carlise grew attached to him in hospital when Edward was dying of Spanish Influenzia. So Carlise took him back to his home and changed Edward. Hope that answers your Question.
Edward Edward does in Breaking Dawn....when Bella is giving birth to Edward's daughter Renesmee.
Edward Cullen formerly Edward Masen was dying of the Spanish Influenza when Carlise Cullen found him in a ward with the dying and changed him into a vampire