Whenever they get the vulnerable groups vaccinated assuming the vaccines remain effective.
I am intrigued as to when the vaccine will start to have an effect on transmission but there is so much we don't know. We don't know how infectious the new variant is, we don't know how effective the Oxford vaccines will be (because there's some suggestion they have hit on a formula), and how the vaccines will affect transmission. We don't know what the supply will be like and whether the UK will even be able to roll it out as effectively as people think.
I would like to think that if the Oxford vaccine is approved it can be rolled out by the end of February. Rope every possible person into the campaign so that the only constraint is supply.
