Collider had a recent interview with Saoirse Ronan about The Host, and although I can’t embed the video here, I’ve posted a transcript of what she said regarding the movie:

On being compared to Melanie or Wanderer:

I’m definitely leaning more towards Melanie than Wanda. I’m maybe not quite as feisty as her, but I think I can be pretty feisty when I want to be.  Yeah.

On making the distinction between Melanie and Wanderer:

With Melanie, she’s very feisty, she’s very much a fighter, and Wanda is the perfect being and is very understanding and positive about everything and all that kind of stuff.  So there was a very clear division between these two characters emotionally and attitude-wise and all that kind of stuff.  With the voice, it was just Melanie, and we went into the sound studio before we started shooting and recorded all over her v.o. (voiceover) and she’s still just as feisty as she was when she was in control of her own body if not more so cause she’s trying to get it back.  We did all that and it was great because I could just react to all that stuff.

On Max Irons and Jake Abel: 

I did work with Jake before.  He was in The Lovely Bones, and we had one scene together.  It was lovely when I heard he was coming into read for it, because he’s lovely and he did a great audition as well so I was chuffed.  And I had met Max a few years before that as well, so it was nice to know that I knew who these guys were, I knew what they were about, you know.  We were all comfortable with each other.  It was great.

You can watch the video at Collider where she also talks very briefly about her other upcoming films, The Grand Budapest Hotel and How to Catch a Monster.