Covid-19 alert level methodology updated

The Joint Biosecurity Centre (JBC), UK Chief Medical Officers (CMOs) and the National Medical Director for England have today revised the UK COVID-19 Alert Level definitions and methodology, to bring them in line with the evolving nature of the COVID-19 pandemic.

As the UK vaccination programme continues and people gain more protection against the virus, it is appropriate the methodology used to assess the risk of COVID-19 across the UK is updated from when it was last published in January 2021.

The current methodology is being updated to take into account the weakening, but persistent, link between COVID-19 cases and severe disease, hospitalisations and deaths, as well as the risk posed by Variants of Concern and Variants Under Investigation.

The UK COVID-19 Alert Level communicates the current COVID-19 public health risk at a UK-wide level. Today’s update is not a change to the UK COVID Alert Level, which remains at Level 3.

The methodology continues to be available on GOV.UK. It sets out the criteria used by the Joint Biosecurity Centre to advise the UK CMOs on the current public health risk in the UK who in turn advise ministers on the UK COVID-19 alert level.

The following changes have been made:

Alert Level 4 definition

Previous definition: A COVID-19 epidemic is in general circulation; transmission is high or rising exponentially.

New definition: A COVID-19 epidemic is in general circulation; transmission is high and pressure on healthcare services is widespread and substantial or rising.

Escalate from Level 2 to Level 3

Previous indicators: Is the UK weekly case rate more than 10 per 100,000 population? Is the national R reliably estimated to be ≥1? Is the doubling time of confirmed new infections less than seven days? Has the number of COVID-19 outbreaks notified in specific UK settings (e.g. care homes, prisons or schools) increased by 20% or more nationally over the previous seven days? Are any cases or clusters detected through sentinel surveillance not linked to a known transmission chain?

New indicators: Is the UKweekly case rate more than 50 per 100,000 population? Is the national R reliably estimated to be ≥1? Is the doubling time of confirmed new infections less than seven days?

Escalate from Level 3 to Level 4

Previous indicators: Is the national R reliably estimated to be R>1? Is the doubling time of confirmed new infections less than seven days? Are COVID-19 related hospital admissions increasing at ≥50% over the same seven-day period? Are COVID-19 related High Dependency Units (HDU)/Intensive Care Units (ICU) admissions increasing at ≥50% over the same seven-day period? Are COVID-19 related total deaths increasing at ≥50% over the same seven-day period? Are there more than 10,000 estimated new infections in the UK per day? Is the UK weekly case rate more than 50 per 100,000 population?

New indicators: Is the UK weekly case rate more than 250 per 100,000 population? Is the national R reliably estimated to be R>1? Is the doubling time of confirmed new infections less than seven days? Are COVID-19 related hospital admissions and occupancy increasing at ≥25% over the same seven-day period? Are COVID-19 related High Dependency Units (HDU)/Intensive Care Units (ICU) admissions and occupancy increasing at ≥25% over the same seven-day period? Are COVID-19 related total deaths increasing at ≥25% over the same seven-day period? Are there more than 30,000 estimated new infections in the UK per day?

De-escalate from Level 4 to Level 3

Previous indicators: Are there estimated to be less than 10,000 new infections per day? Is the UK weekly case rate less than 25 per 100,000 population? Has the national estimate of R been consistently <1 for at least four weeks? Have the observed number of new daily COVID-19 confirmed infections, hospital admissions, ICU admissions and deaths been on a downward trend for the last 4 weeks?

New indicators: Arethere estimated to be less than 30,000 new infections per day? Is the UK weekly case rate less than 125 per 100,000 population? Have the observed number of new daily COVID-19 confirmed infections, hospital admissions, ICU/HDU admissions and deaths been on a downward trend, or stable at a low level, for the last 4 weeks? Has COVID-19 hospital occupancy and ICU/HDU occupancy been on a downward trend, or stable at a low level, for the last 4 weeks?

De-escalate from Level 3 to Level 2

Previous indicators: Is the UK weekly case rate less than 10 per 100,000 population? Has the national estimate of R indicated a downward trajectory for the last four weeks? Has the total count of defined outbreaks been in decline in all Devolved Nations and PHE regions for at least four weeks? Have the number of new daily COVID-19 infections, hospital admissions, Intensive Care Unit admissions and deaths been on a downward trend, or been stable at a low level, for the last 4 weeks?

New indicators: Isthe UK weekly case rate less than 25 per 100,000 population? Have the observed number of new daily COVID-19 confirmed infections, hospital admissions and deaths been on a downward trend, or stable at a low level, for the last 4 weeks? Has COVID-19 hospital occupancy been on a downward trend, or stable at a low level, for the last 4 weeks?