These two little fuckers are some of the most selfish and wilfully oblivious characters in horror

Imagine literally seeing what happened as a result of your infected mother spreading literally any bodily fluid to a human being, ending up in the exact same condition, and selfishly evacuating yourselves to a country which the disease hadn't touched and not even having the decency to cover your mouth with a piece of clothing on the helicopter. The boy probably caused the heli to crash by coughing over his sister or whatever.

There's no question about the fact that the film is blatant in telling you that these two are the reason the infection spread, the channel tunnel thing is such a reach in comparison, given how it was probably sealed off during the events of the first film.