Honestly, what faults I might have had with the first movie were monumentally dwarfed by the second one. Just yesterday, before I went and saw the movie, I was watching some of the interviews and they talked about people wanting a more cerebral and plausible story line than people coming back from the grave. Well let me tell you that this is definitely not it.
No spoilers but let me ask you this...
Where are the guards for the only living infected person?
Why are kids in these movies so stupid that they don't respond to their own names?
If its supposed to be a secure location why aren't all the doors locked?
Floating chemical gas > than being in a car with vents and using a cloth to cover your mouth.
There are more issues for sure but I don't want to spoil it for anyone wanting to see this in the theatre. I really was disappointed with the way they told this story because it could have been more cerebral if they were going for it. But it felt like they are just taking the easy path to a dumb conclusion and setup for 28 months later. (That one I might not make it too)