Delaying step 4 would have a dramatic impact on the peak number of hospital admissions

This image from the Warwick roadmap paper shows the impact of different delays to the start of step 4 on the number of daily hospital admissions in England

Step 4

Peak

Wave 2

Peak

Wave 1

Step 2

Step 3

Step 4

Peak Wave 2

Peak Wave 1

Image from University of Warwick. Projections assume Delta variant is 56% more transmissible than the Alpha variant, with two-dose vaccine effectiveness against hospital admission of 90-91%