The paper is the one that the Helicopter pilot had from his son.
I think the director showed this just to set something like: "This scene is the days after the pilot taking the survivors from GB to FRance across the Channel". (Remember that the soldier ask him to take the kids across the channel, not to the base.

And there's a lot of possibilities to the re-infection. The kid could have kissed a girl in France, the military or health ministry personal could have done tests to him and the virus was released for accident, the virus could have evolved and now can infect by touch or air, et cetera. Just to give a few possibilities.

That's all, for now, folks.

Celso Bessa

28 Days and 28 Weeks Later are among my prefered movies. Specially the first one, with that incredible soundtrack (this is the only thing that i think is "lousy" in the 28 Weeks).

I could not disagree about the "disbelief" thing. I had to argue about something like that in the last time i watched the DVD with some friends at home. And there are other problems: both of movies demmands that people watch them with more than just the eyes, and seems like people are getting less and less willing to use the brains when watching movies, specially horror/sci-fi movies. I think this is getting so serious, that when people ask me about 28 Days / 28 Weeks, a warn then: "it's a drama movie, with 'something-like-zombies'. You need brains to watch it. Wanna give it a try?".

Best Regards, from Brasil/Brazil.

Celso Bessa

Now we could say that the kid accidentally released the virus to the rest of the world by some miens that I do not know.

OR

We cold say that the little boy went insane and deliberately infected people. I know that this is extreme and I may be wrong, but it makes perfect sense to me because I noticed that at the end the director shows a paper that says "For Dad."

PS: Anyone would go insane with the experiences that kid had, at that age.