The timing of step 4 has an impact on hospital admissions

This chart 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

21 June

Step 4

(21 June)

Black

Step 4

(19 July)

Orange

28 June

5 July

12 July

19 July

Peak

wave 2

26 July

2 August

9 August

Peak

wave 1

16 August

23 August

95%

confidence

21 June

Step 2

Step 3

Step 4

(21 June)

Black

Step 4

(19 July)

Orange

28 June

5 July

12 July

Peak wave 2

19 July

26 July

95%

confidence

2 August

Peak wave 1

9 August

16 August

23 August

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%