Professor Philip Nolan:

A lot of it is in the letter. I am not avoiding the question. The truth is that it is progressive and rapidly so. There are no actual milestones. If one looks at the layout of the vaccination programme, the rate at which the population is vaccinated ramps up very quickly over a short number of weeks. We go from having 25% to 50% to 75% of the population effectively vaccinated over the course of less than 12 weeks under the current programme.