The movie is about

It is set after the events of the first film, depicting the efforts of NATO military forces to salvage a safe zone in London, the consequence of two young siblings breaking protocol to find their infected mother, and the resulting reintroduction of the Rage Virus to the safe zone.

The deleted scenes weren't on the dvd extras or blu-ray

Look at this old trailer THE FIRST TRAILER OF THE MOVIE

2:21 in the trailer

https://www.dailymotion.com/video/x1n3bq

It shows the blue guy has been now infected shouting at the screen

1:49 in the trailer

https://www.dailymotion.com/video/x1k120

I don't know if this was deleted but I never since this scene

https://youtu.be/7ueS-kE3h3Q?t=8

The boy that got the whole group dead was infected

here is an image from the wiki

Boy from sandford

Boy gets infected

He was the one who attracted the infected to the group

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