The Returned (2013)

Kate and Alex have jobs they like, a fancy high rise apartment and are crazy about each other.  What they haven't told anyone is that Alex is one of the Returned, aka people bitten by zombies who keep from turning into the walking dead by taking daily injections of an experimental serum.

Kate is a doctor who works in a unit that treats the Returned. This  gives her access the serum, as well as the most up to date testing and treatment methods. The serum is made from fluids from the infected and the more people that return, the less serum is available.  Currently the unit is working on a synthetic serum that they hope to have before the need arises.

But when there is a serum shortage, the Anti-Return League employs fear mongering to generate public panic.  The names and addresses of the returned are stolen from a government database, and someone starts killing the returned on the list. Kate and Alex fear that someone will show up at their door looking for Alex, and due to the limited supply of serum, she doesn't know if she can get more before their supply runs out.

Alex is kind of a twit. The guy gets bitten when he goes into a store. It appeared no one was there, and then he found the owner at the bottom of the basement stairs.  So later in the film, when he goes into a gas station, and it appears no one is there, you'll want to punch him when he goes to investigate. Did he learn nothing from this first experience?  And what happens if they returned are bitten again? Does it matter?