COVID-19 infection survey of the UK general population

Plain English summary of protocol

Background and study aims
COVID-19 is a condition caused by the coronavirus (called SARS-CoV-2) that was first identified in late 2019. This virus can infect the respiratory (breathing) system. Some people do not have symptoms but can carry the virus and pass it on to others. People who have developed the condition may develop a fever and/or a continuous cough among other symptoms. This can develop into pneumonia. Pneumonia is a chest infection where the small air pockets of the lungs, called alveoli, fill with liquid and make it more difficult to breathe.
In 2020, the virus had spread to many countries around the world and neither a vaccine against the virus nor specific treatment for COVID-19 had been developed. As of April 2020, it was advised that people minimize travel and social contact, and regularly wash their hands to reduce the spread of the virus. Since then, multiple phases of vaccinations have been rolled out, restrictions have been lifted, and many people have returned to their usual daily activities with increased social contact.
Groups who are at a higher risk from infection with the virus, and therefore of developing COVID-19, include people aged over 70 years, people who have long-term health conditions (such as asthma or diabetes), people who have a weakened immune system and people who are pregnant. People in these groups, and people who might come into contact with them, can reduce this risk by following the up-to-date advice to reduce the spread of the virus.
The COVID-19 pandemic has had, and continues to have, a profound impact across the UK. This study aims to find out how many people are still getting the infection and how many are likely to have had the infection, even if they haven’t realised it at the time. This is particularly important as more people have now had multiple vaccinations against COVID-19. Although the vaccines work very well, they are not 100% protective, and it is necessary to monitor how well they work in the real-world.
One way to find out whether a person has an infection is to directly look for the microbe in their nose and throat. The main test used to diagnose COVID-19 uses a swab taken from someone’s nose and throat. Once an individual has recovered from the infection, the virus cannot be found any longer. One way the body fights infections like COVID-19 is by producing small particles in the blood called “antibodies”. It takes 2-3 weeks for the body to make enough of these antibodies to fight the infection. But once a person recovers, they still stay in the blood at low levels and give some protection against further infection. Getting vaccinated against COVID-19 is another way that people can get antibodies that can protect them against getting COVID-19. Therefore scientists try to measure levels of both the virus and these antibodies to work out who has COVID-19 now (with or without symptoms) and who has had it in the past, or had developed antibodies against it after getting vaccinated.
The aim of this study is to find out how many people of different ages across the UK have COVID-19 over time, particularly as people have returned to work or school and as more and more people get multiple vaccinations, and how many have had COVID-19 in the past. The researchers will do this by testing for the virus in the nose and throat of people and by measuring levels of antibody in the blood. They also want to find out how many people have COVID-19 with symptoms or without knowing they have the infection because they don’t have any symptoms. They want to do this in a group of people that reflects the population of the UK – so a range of ages and places where people live.

Who can participate?
Randomly selected households from all four countries of the UK have been invited to participate over the course of the study (see participant inclusion criteria section). We are not actively recruiting new participants at this time.

What does the study involve?
The researchers will ask everyone aged 2 years or older in each randomly selected household to have a nose and throat swab, and for those aged 12 years and older to answer a few short questions (parents/carers will answer for younger children). Until May 2022, this was done at a home visit undertaken by a trained individual. From July 2022, sample kits are posted to all participants, with questions being completed online or over the telephone. Those aged 12 years and older can take their own swabs using self-swabbing kits, and parents/carers will use the same kits to take swabs from their children aged 2-11 years. Adults and children aged 8 and over in a subset of these enrolled households are invited to also give a sample of blood, taken by a finger prick by the participants themselves. Posting sample kits to participants means swab and blood samples can be collected at every month, including in households where anyone has symptoms or is isolating/shielding.

The researchers will ask everyone joining the study to do the tests, and complete the questionnaire every week for the first month and then every month until the study ends. This is to find out how rates of infection and immunity change over time in individual people, and whether they can get the virus again with or without having symptoms. Participants are also followed up through their electronic health records for up to 15 years from their final study assessment. Consent for this electronic follow-up is required to join the study.

What are the possible benefits and risks of participating?
The possible benefits are that participants will get results from tests for SARS-CoV-2 that would not usually be done. This includes nose and throat swab test results for all participants and S-antibody blood test results for those invited to give a sample of blood. A small amount of compensation will be offered to each participant per assessment, to reflect their time and inconvenience. We will offer participants the option not to receive this compensation if they prefer.
The main disadvantage of taking part is the time and inconvenience of having to take samples and complete the questionnaire and either return them to a priority post box or organise a courier collection from home. When blood is taken from a finger prick, participants may need to prick several fingers to get enough blood and fingers may be sore. There is also a possibility of fainting.

Where is the study run from?
Office for National Statistics and the University of Oxford (UK), and delivered by IQVIA.

When is the study starting and how long is it expected to run for?
Assessments will be conducted from April 2020 to March 2023; follow-up through electronic health records will be through March 2038.

Who is funding the study?
Funding for the survey in England, Wales, Northern Ireland and Scotland is provided by the UK Health Security Agency and the Department of Health and Social Care, as agreed with the Treasury. In-kind support is provided by the Welsh Government, the Department of Health on behalf of the Northern Ireland Government, the Scottish Government, the Office for National Statistics, the Northern Ireland Statistics and Research Agency, the University of Oxford (in particular through the Oxford National Institutes of Health Research (NIHR) Biomedical Research Centre and the NIHR Health Protection Research Unit in Antimicrobial Resistance and Healthcare-Associated Infections in collaboration with the UK Health Security Agency [NIHR200915]).

Who is the main contact?
This study is not recruiting at this time. Please do not contact the research team as they will not be able to respond.

Study website

Contact information

Prof Ann Sarah Walker
Scientific

Microbiology Research, Level 7
John Radcliffe Hospital
Headley Way
Oxford
OX3 9DU
United Kingdom

ORCID ID	0000-0002-0412-8509
Email	COVID-19@ons.gov.uk

Study information

Eligibility

Locations

Countries of recruitment

• England
• United Kingdom

Study participating centre

Sponsor information

University of Oxford
University/education

Joint Research Office
1st Floor, Boundary Brook House
Churchill Drive
Headington
Oxford
OX3 7GB
England
United Kingdom

Phone	+44 (0)1865 616480
Email	ctrg@admin.ox.ac.uk
Website	http://www.ox.ac.uk/
"ROR"	https://ror.org/052gg0110

Funders

Funder type

Government

Results and Publications

Study outputs

Editorial Notes

13/03/2023: Total final enrolment, protocol and participant information sheet added.
28/02/2023: The following changes were made to the trial record:
1. The study hypothesis, interventions, primary and secondary outcome measures, and publication and dissemination plan were updated.
2. The overall trial end date was changed from 31/07/2023 to 31/03/2038.
3. The target number of participants was changed from ~500,000 to 'The number of participants providing swab and blood samples each month has varied over the course of the study, targeting specific degrees of precision in estimates of swab and antibody positivity.
From April 2022, the targets were as follows:
• Swab target: up to (maximum) 227,300 swab samples taken from individuals 2 years and older every 28 days in England, 15,650 in Wales, 10,050 in Northern Ireland and 23,200 in Scotland (maximum 276,200 total across the UK every 28 days, maximum 300,000 swab samples in total across the UK per month);
• Blood target: up to (maximum) 90,850 blood samples taken from individuals 8 years and older every 28 days in England, 6,300 in Wales, 4,150 in Northern Ireland and 9,200 in Scotland (maximum 110,500 in total across the UK every 28 days, maximum 120,000 blood samples in total across the UK per month)'
4. UK Health Security Agency was added as a funder.
5. IPD sharing statement added.
6. The plain English summary was updated accordingly.
19/11/2021: Preprint reference added.
21/09/2021: Preprint reference added.
11/06/2021: Preprint reference added.
04/05/2021: The following changes were made to the trial record:
1. The recruitment end date was changed from 23/04/2021 to 31/01/2022.
2. The overall end date was changed from 23/04/2023 to 31/07/2023.
3. The plain English summary was updated to reflect these changes.
19/03/2021: Preprint reference added.
16/12/2020: Publication reference added.
14/09/2020: Trial's existence confirmed by the NIHR.