Presentation for health secretary Sajid Javid drawn up by the UK Health Security Agency on 7 December

Mechanical calculations to illustrate required timing of restrictions under simple assumptions

Desire to keep daily Covid-19 admissions with Omicron below

1,000

3,000

5,000

Assume overall vaccine efficacy against severe disease results in an infection hospitalisation rate of

0.5

1

percent

2

0.5

1

percent

2

0.5

1

percent

2

Last date at which stringent national measures can be introduced while keeping admissions below threshold

13

10

December

8

17

14

December

12

19

16

December

14

Daily Omicron infections on date measures required (lags mean these won’t be observed on that day)

47

20

thousand

12

143

62

thousand

36

248

108

thousand

62

Mechanical calculations to illustrate required timing of restrictions under simple assumptions

Desire to keep daily Covid-19 admissions with Omicron below

Assume overall vaccine efficacy against severe disease results in an infection hospitalisation

rate of

Last date at which stringent national measures can be introduced while keeping admissions below threshold

Daily Omicron infections on date measures required (lags mean these won’t be observed on that day)

0.5%

13 Dec

47,000

1,000

1%

10 Dec

20,000

2%

8 Dec

12,000

0.5%

17 Dec

143,000

3,000

1%

14 Dec

62,000

2%

12 Dec

36,000

0.5%

19 Dec

248,000

5,000

1%

16 Dec

108,000

2%

14 Dec

62,000