Twenty thousands households in England will be asked to take part in a study to track the spread of Covid-19.
The aim is to further understand the rate of infection and the number of people who have developed immunity across the UK.
Who will take part?
Participants will be chosen from a list of people who have already taken part in Office of National Statistics' (ONS) surveys in the past, and will represent the diversity of the wider population in England.
It will later be expanded to include the whole of the UK.
How will the tests be carried out?
A healthcare worker will travel to individual households to take nose and throat swabs from each person living there.
If a person is found to have Covid-19, they will then be tested on a weekly basis for five weeks and then monthly for a year.
Eventually, it is hoped, there will be 300,000 participants involved in the programme.
In addition to this, adults from 1,000 households will have blood samples taken to ascertain how many people have created antibodies to Covid-19, how long they last and if it provides them with future immunity form the virus.
Who will produce the results?
The tests will be checked by the University of Oxford.
The study is run in conjunction with the ONS and Department of Health, with its early findings to be released in May.
What has the government said?
Health Secretary Matt Hancock, who launched the scheme on Thursday, said: "Understanding more about the rate of Covid-19 infection in the general population, and the longer-term prevalence of antibodies, is a vital part of our ongoing response to this virus.
"This survey will help to track the current extent of transmission and infection in the UK, while also answering crucial questions about immunity as we continue to build up our understanding of this new virus.
"Together, these results will help us better understand the spread of the virus to date, predict the future trajectory and inform future action we take, including crucially the development of ground-breaking new tests and treatments."
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