The central forecast is based on the following:
a higher infection rate at the end of the lockdown and a less effective Test, Trace and Isolate (TTI) system necessitate keeping a more stringent set of public health restrictions in place over the winter;
these may vary regionally and temporally but are broadly the same as remaining at the equivalent of England’s pre-lockdown Tier 3 until the spring;
the arrival of warmer weather then allows an easing of the restrictions;
an effective vaccine becomes widely available in the latter half of the year, permitting a gradual return to more normal life, though at a slower pace than in our upside scenario;
there is also a lasting adverse impact of the pandemic on the economy.