Suddenly, there is a credible case for a vaccine-led economic recovery. Modern science has delivered what must certainly be one of the greatest miracles of my long lifetime. Just as Covid-19 dragged the world economy into the sharpest and deepest recession on record, an equally powerful symmetry on the upside now seems possible.

If only it were that easy. With Covid-19 still raging - and rates of infection, hospitalisation, and death now spiralling out of control (again) - the near-term risks to economic activity have tipped decidedly to the downside in the United States and Europe. The combination of pan...