Contamination — Jamie Thornton

More than anything, eighteen-year-old Corrina wants Dylan to love her as much as her parents loved each other. But when a new virus unleashes violence that devastates their neighborhood, Dylan is kidnapped and Corrina uncovers a terrible secret.

A crude vaccination, and now Corrina's immune from the virus ravaging the city -- but the cure changes her memories in unexpected ways.

With help from a group of runaways, Corrina must survive a world gone mad if she's to find the boy she loves. But when Dylan discovers what she's become, will he still love her?

Book 2 in the post-apocalyptic Young Adult series where the runaways are the heroes, the zombies aren't really zombies, and you can't trust your memories -- even if they're all you have left.