The Winter Coronavirus (COVID-19) Infection Study (Winter CIS) is a sample-based household study, involving participants from the previous Coronavirus (COVID-19) Infection Survey who live in England and Scotland and who agreed to be contacted to take part in future research studies.

The statistics produced by the Winter CIS are official statistics in development. This means they are new official statistics that are undergoing a development and will be tested with users, in line with the standards of trustworthiness, quality and value in the Code of Practice for Statistics.

For more information about the strengths and limitations of the data, methods used, and data uses, see our Winter Coronavirus (COVID-19) Infection Study Quality and Methodology Information report.

Publications that use these data

Winter Coronavirus (COVID-19) Infection Study: estimates of epidemiological characteristics, England and Scotland: 2023 to 2024
Report | Fortnightly
This fortnightly publication by the UK Health Security Agency describes the prevalence of COVID-19 in England and Scotland.

Viral respiratory diseases (including influenza and COVID-19) in Scotland surveillance report
Report | Weekly
This weekly release by Public Health Scotland presents epidemiological information on respiratory infection activity, including COVID-19, across Scotland.

National flu and COVID-19 surveillance reports: 2023 to 2024 season
Report | Weekly
National influenza and COVID-19 report, monitoring COVID-19 activity, seasonal flu and other seasonal respiratory illnesses.

Related links

The Winter Coronavirus (COVID-19) Infection Study (Winter CIS): publications explained
Report | Published 21 December 2023
Information about the separate publications that the Office for National Statistics (ONS) and UK Health Security Agency (UKHSA) will be producing to share the results from the joint Winter Coronavirus (COVID-19) Infection Study (Winter CIS).

Winter Coronavirus (COVID-19) Infection Study QMI
Methodology | Released 18 January 2024
Quality and Methodology Information (QMI) for the Winter CIS, detailing the strengths and limitations of the data, methods used, and data uses.