Professor Philip Nolan:

What we modelled is the current vaccination programme as published but obviously we will re-run the models on the basis of recent decisions. The fundamental thing shown by that model is that we should not be thinking in terms of benchmarks of 25%, 50% or 75% of the population vaccinated and then we can do one big thing. What the model shows is that the impact of vaccination is progressive. The more people that are vaccinated, the harder and harder it is for the virus to transmit. Ultimately, we might get to the point of herd immunity, where the virus cannot transmit and sustain the epidemic but far in advance of that, we begin to find fewer cases-----