Doomsday (2008)

Authorities brutally quarantine a country as it succumbs to fear and chaos when a virus strikes. The literal walling-off works for three decades - until the dreaded Reaper virus violently resurfaces in a major city. An elite group of specialists , captained by Eden Sinclair (Rhona Mitra), is urgently dispatched into the still-quarantined country to retrieve a cure by any means necessary. Shut off from the rest of the world, the unit must battle through a landscape that has become a waking nightmare.