system
Given the following post, respond as if you're commenting on Reddit:
human
[28 weeks later] How they should have managed the UK's repopulation?

In the movie, they totally scewed this up. I think, for starters they should have moved the population away from Central London.

Maybe a small commuter town which would be way easier to secure than a massive city. Pick one near a RAF base for plane movements and possible evacuations.

Also, establish a no man's land all around the town, with automated machine guns and minefields for safety.

Finally, residents get their own apartments with secure prison.-like doors. The emergency protocol means that everyone runs back to their apartment and locks inside.

Anyone caught still running outside gets shot.
gpt
Hindsight is 20/20. They had no reason to suspect the whole carrier aspect of the virus and got completely blindsided. It's easy to look back and critique it when you happen to know the threat was still present. 

That being said, it was the British government. Screw ups are second nature to them.