28 Weeks Later (2007)

28 Weeks Later expands the world introduced in 28 Days Later, depicting the fragile attempt to repopulate London after the Rage virus outbreak. Directed by Juan Carlos Fresnadillo, the film follows the catastrophic consequences of reintroducing civilians into a quarantined city. Intensifying the scale and brutality, the film remains rooted in survival horror and viral apocalypse.

Från IMDB:
Six months after the rage virus was inflicted on the population of Great Britain, the US Army helps to secure a small area of London for the survivors to repopulate and start again. But not everything goes according to plan.