I agree with Rorschach that mutations will be very hard to deal with but we must do everything possible so as the risk is reduced, this means people need to prove negative before entering the Uk and we do the same before going abroad. It may want to mutate but we need to make it difficult and not an open invite.
You have to be careful using phrases like "everything possible" because clearly you don't believe that. If you wanted to do everything possible you would lock everyone up in their homes from birth till death. I am assuming you would like some freedom?