This is really turning into a cracking series and I'm finding it interesting seeing how posters here analyse the show.
I agree. Top thread. You should check out the Utopia thread on the Cult, Sci-fi, Fantasy forum too.
If we are to believe Jessica is a vaccinator... was she created for that reason? To be a walking, talking human vaccine lol? Does that mean Arby is a vaccine too? Maybe that's what Letts meant when he said Arby was "special".