The Winter CIS was launched jointly by the UK Health Security Agency (UKHSA) and the Office for National Statistics (ONS) in November 2023 to deliver real-time prevalence and positivity data to aid the surveillance of COVID-19 in the community and help understand the winter pressures on the NHS.

The study collects data through self-reported lateral flow device (LFD) results and questionnaire responses from approximately 150,000 participants across England and Scotland, providing up to 30,000 LFD test results per week.

The latest report estimates a prevalence of 4.2% across the total population in England and Scotland. This means that approximately 1 in every 24 people could test positive for COVID-19 infection at the current time.

Prevalence rates were highest in people aged 18 to 44 years, and the highest prevalence regionally was found in London.

UKHSA is urging all those eligible to come forward for a seasonal COVID-19 vaccine before the window closes on 31 January 2024.

You are eligible for a COVID-19 vaccine if you are:

• aged 65 years or over (by 31 March 2024)
• aged 6 months to 64 years and are at increased risk
• living in a care home for older adults
• a frontline health or social care worker
• aged 16 to 64 years and are a carer
• aged 12 to 64 years and live with someone with a weakened immune system

Professor Steven Riley, Director General for Data and Surveillance, UKHSA said:

At this time of year, the cold weather, shorter days and increased socialising mean that the potential for transmission of respiratory viruses like COVID-19 is particularly high. This, as well as the possible impact of new variants, means it's not unexpected to see cases increasing.

If you are showing symptoms of COVID-19 or other respiratory illnesses, you should try to limit your contact with other people as much as possible, especially those who are older or more vulnerable.

It's important that those people who are most at risk of severe illness and hospitalisation as a result of COVID-19 come forward for their seasonal vaccination to make sure they have the best possible protection this winter. You can get a vaccine through your GP, by booking with a local NHS vaccination service, or you can find a COVID-19 vaccination walk-in site."

More information

Although the main vaccine delivery programme has now ceased and you can no longer book a seasonal COVID-19 vaccine online or by calling NHS 119, you may still be able to book a COVID-19 vaccine with a local NHS vaccination service, or you can find a COVID-19 vaccination walk-in site.

The last date you will be able to get your seasonal COVID-19 vaccine is 31 January 2024.

After Christmas, UKHSA and ONS will release the next set of Winter CIS results on 11 January. This will be followed by another report on 18 January and will revert to fortnightly thereafter.

The UKHSA estimates are based on the same underlying data as the positivity numbers reported by ONS. UKHSA's estimates of prevalence account for the known sensitivity of the LFD assay and the composition of the study cohort.