Yes, if you REALLY MUST! It's the right time of year before it starts setting new growth.
Personally, I would only contemplate pruning a camellia if it was threatening to come through a window or was in danger of falling over and hurting itself - in other words, if it was very big and unruly.

Camellia hedge? I can't see Camellias working as a hedge in the long term, unless you are happy for them to just grow away. As Urbanite states it is not normal to prune a Camellia.