I am not anti-vaccination by any stretch of the imagination, but I am sure I would be less enthusiastic to take a vaccine that was only 50-60% effective in trials (I probably would still take it mind). If the vaccine only provided protection for a few months, I'd be in two minds. So, if I was asked in that survey, I probably wouldn't be in the half of Britons who would definitely have the vaccine - purely because of a lack of detail at the present moment.