Condition category
Infections and Infestations
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status

Plain English Summary

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 has spread to many countries around the world and neither a vaccine against the virus or specific treatment for COVID-19 has yet been developed. As of April 2020, it is advised that people minimize travel and social contact, and regularly wash their hands to reduce the spread of the virus.
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.
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 – with other infections, this is what helps them avoid getting the same infection again, although it is not yet known whether the same is true for COVID-19. So 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.
The aim of this study is to find out how many people of different ages across the UK have COVID-19 now, particularly as people start going back to work or school, 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 over the coming months – either 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?
The researchers will begin by inviting 20,000 households to participate with an assumed 50% opt-in rate, and a target enrolment of 10,000 households (2,500 per week over around 1 month). After this, they will successively ask more and more randomly selected households from all four countries in the UK.

What does the study involve?
The researchers will ask everyone aged 2 years or older in each household to have a nose and throat swab, and for those aged 12 years and older to answer a few short questions at a home visit undertaken by a trained individual (parents/carers will answer for younger children). 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. This is to reduce the risk to the survey team members. The researchers will ask adults aged 16 years or older from a randomly selected 10-20% of households to also give a sample of blood which will be taken by a trained nurse, phlebotomist or healthcare assistant. The researchers will take swabs from all households, whether anyone is reporting symptoms or not. They will not take blood from anyone in a household where someone has symptoms compatible with COVID-19 infection, or is currently self-isolating or shielding, to make sure that study staff stay at least 2 m away from them at all times. The survey team members will use all the recommended precautions to protect themselves and everyone in the household from getting the virus.
The researchers will ask people who have this first home visit whether they would be happy to have the same kind of visit and nose and throat swabs repeatedly, every week for the first month (swab and questionnaire only, no blood draw), and then every month from their first visit for a year (including monthly blood draws for those with blood taken originally). 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 1 year from their final visit.

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. The main disadvantage of taking part is the time and inconvenience of having a member of the survey team visit their home. When blood is taken there is a possibility of bruising and/or fainting. The survey has been designed to make the risk of catching COVID-19 as low as possible – that is why the survey team use the recommended precautions and PPE and avoid entering people’s homes unless it is necessary to take blood. However, even with this, it is possible that there is still a small risk of a participant getting COVID-19 from a survey team member (or a survey team member getting it from someone in the survey).

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

When is the study starting and how long is it expected to run for?
April 2020 to April 2023

Who is funding the study?
Funding for the survey in England, Wales, Northern Ireland and Scotland is provided by 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 Public Health England [NIHR200915]) and Public Health England.

Who is the main contact?
Unfortunately, this study is not recruiting public volunteers at this time. This is because the research isn’t ready for volunteers yet or the researchers are directly identifying volunteers in certain areas or hospitals. Please do not contact the research team as they will not be able to respond. For more information about COVID-19 research, visit the Be Part of Research homepage.

Trial website

Contact information



Primary contact

Prof Ann Sarah Walker


Contact details

Microbiology Research
Level 7
John Radcliffe Hospital
Headley Way
United Kingdom

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number

CPMS 46962, IRAS 283248

Study information

Scientific title

Incidence of COVID-19 (SARS-CoV-2) infection and prevalence of immunity to COVID-19 (SARS-CoV-2) in the UK general population as assessed through repeated cross-sectional household surveys with additional serial sampling and longitudinal follow-up - an Office for National Statistics Survey



Study hypothesis

The main aims of this observational study are
1. To estimate the prevalence of symptomatic and asymptomatic SARS-CoV-2 infection in the general population and how this varies over time
2. To estimate the incidence of new symptomatic and asymptomatic SARS-CoV-2 infection in the general population, and how this varies over time
3. To estimate immunity to SARS-CoV-2 in the general adult population and how this varies over time, as reflected by immunoglobins

Ethics approval

Approved 21/04/2020, Berkshire B Research Ethics Committee (The Old Chapel, Royal Standard Place, Nottingham, NG1 6FS, UK; +44 (0)207 1048310;, REC ref: 20/SC/0195

Study design

Surveillance study based on repeated cross-sectional surveys of representative households across the UK, with nested longitudinal serial sampling of participants providing additional optional consent for this

Primary study design


Secondary study design

Longitudinal study

Trial setting


Trial type


Patient information sheet


COVID-19 (SARS-CoV-2 infection)


Consenting adults, adolescents and children aged 2 years or older in randomly selected households will self-swab their throat and nose and be asked some short questions by a survey team member. A random percentage of households will also be approach for additional consent for blood draws in those aged 16 years or over. Depending on the consent/assent provided by each individual participant, their involvement may be (i) for one home visit only (cross-sectional survey) (ii) for five home visits (cross-sectional survey then optional to repeat visits every week for the next month) or (iii) for 16 home visits (cross-sectional survey then optional to repeat visits every week for the next month and then monthly for a total of 12 months from the first visit). All participants will provide follow-up through available routine electronic health records for one year from their final study visit to assess use of healthcare, results from other tests for COVID-19 infection and mortality.

Intervention type



Drug names

Primary outcome measure

Presence vs absence of SARS-CoV-2 virus assayed from a nose and throat swab using a polymerase chain reaction (PCR) test, every calendar week from the start of the study for 1 year (note: the outcome measure is at the population level, not the individual level as this is a surveillance study)

Secondary outcome measures

1. Incidence of new presence of SARS-CoV-2 virus measured from a nose and throat swab using a PCR test, separately in previously negative and previously virus-positive individuals (to estimate re-infection after clearing the virus), over calendar time from the start of the study for 1 year
2. Immunity to SARS-CoV-2 measured from blood using an enzyme-linked immunosorbent assay for IgG antibodies, over calendar time from the start of the study for 1 year
3 Inpatient admissions measured from centrally stored hospital records (Hospital Episode Statistics) over 1 year from the final study visit
4. Outpatient attendances measured from centrally stored hospital records (Hospital Episode Statistics) over 1 year from the final study visit
5. A&E attendances measured from centrally stored hospital records (Hospital Episode Statistics) over 1 year from the final study visit
6. Consultations with a General Practitioner measured from centrally stored hospital records (Hospital Episode Statistics) over 1 year from the final study visit
7. Overall mortality and cause of death as measured from centrally stored records (Office for National Statistics) over 1 year from the final study visit

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Adult, adolescent or child aged 2 years or older, male or female
2. Currently resident in a household where a household member has participated in an ONS or NISRA Survey and has consented to be approached for future research or where the household has been randomly selected from databases of addresses. ‘Currently resident’ is defined according to 2011 Census definitions, specifically, a ‘resident’ is defined as a person who typically stays overnight in the address at least 4 nights out of 7 and a ‘household’ is defined as one person living alone; or a group of people (not necessarily related) living at the same address who share cooking facilities and share a living room or sitting room or dining area
3. If 16 years or older: Participant is willing and able to give informed consent for participation in the study.
4. If 2-15 years at last birthday: A parent/carer is able to give informed consent for participation in the study; those aged 10 years and older should also provide assent.

Participant type

Healthy volunteer

Age group




Target number of participants


Participant exclusion criteria

Does not meet inclusion criteria

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Office for National Statistics
1 Drummond Gate Pimlico
United Kingdom

Sponsor information


University of Oxford

Sponsor details

Joint Research Office
1st Floor
Boundary Brook House
Churchill Drive
United Kingdom
+44 (0)1865 616480

Sponsor type




Funder type


Funder name

Department of Health and Social Care

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

1. Weekly publication of positivity rates and incidence of new infection in previously negative participants in Office for National Statistics bulletins; as summarised on
2. Monthly publication of additional information from the study in Office for National Statistics articles; also summarised on
3. Planned publications in high-impact peer-reviewed journals.
4. The protocol is available at There won’t be a separate analysis plan.

IPD sharing statement
The data sharing plans for the current study are unknown and will be made available at a later date.

Intention to publish date


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

1. April to November 2020 interim results in (added 16/12/2020)

Publication citations

Additional files

Editorial Notes

16/12/2020: Publication reference added. 14/09/2020: Trial's existence confirmed by the NIHR.