Suddenly Immortal

Maddi just left school one day and fumbles with her keys. After they drop to the ground and she picks them up, some one shows up behind her, biting into her neck. The discomfort of the overall bite was clouding up her mind, but the pleasure behind the bite was engulfing her mind even quicker.
The next morning when she woke, she realized something was different. Looking in the mirror, she found the difference: she was indeed a vampire