FAQ

Yes, this series is a remake of Survivors (1975) which ran on BBC television from 1975-77. The series was created by Terry Nation, who also wrote a tie-in novelization after the first series was shown. However, Hodges and the producers of the 2008 remake claim to have only used Nation's novelization as the basis for their production, and are preferring to call it a "reimagining" rather than a remake. However, since Terry Nation's TV series was broadcast before his novelization was published, the source material is indeed the original TV series - regardless of what Hodges claims. The premise and many of the characters are still the same as the original series, though it has been updated in various ways to make it more contemporary. Hodges has effectively "developed" the new series based on Terry Nation's creation.

As with real viruses, immune-people often have to catch the virus and allow their body to fight it off while not being affected by it later. This would often involve you undergoing the milder symptoms (in this case near-death) while your body gets rid of the virus. Abby obviously caught the virus, probably while within the packed bus, and she received most of the symptoms (feeling faint, general sickness, symptoms of most flus) but her body was strong enough to stop it without dying. This may have also occurred with the other survivors, but they may just have been asleep during fighting of the virus as weren't aware of ever catching it.