The end (spoiler)
we see at the end that the infected are starving to death. So how come 28 weeks later was made ?
"The only thing a gun does is focusing an explosion in one direction"
Because Robert Carlyle's character's wife in the sequel was a carrier. Not all Infected were starving depending on when they became infected. The few we saw on that aerial shot of the first film near the end were malnourished but there must have been others after the army soldiers became infected.
The young kid was also a carrier and I felt a third movie was due out because the helicoptor showed signs of a disaster. It was therefore transferred to Paris, presumably by the young boy.
"Has anyone seen my wife?" - Columbo