Across all four UK countries, there is a clear pattern between vaccination and testing positive for COVID-19 antibodies
Modelled percentage of adults: who tested positive for antibodies to SARS-CoV-2, who have received one or more doses of a COVID-19 vaccine, and who were fully vaccinated; UK countries, 7 December 2020 to 29 August 2021
An estimated 93.6% of the adult population in England, 91.2% in Wales, 91.9% in Northern Ireland and 93.3% in Scotland tested positive for COVID-19 antibodies in the week beginning 23 August 2021. The presence of antibodies suggests a person previously had COVID-19 or has been vaccinated.
Estimated vaccination rates remained high or continued to increase in the week beginning 23 August 2021. Across the four UK countries, 92.7% to 94.1% had received at least one dose of a COVID-19 vaccine and 81.7% to 86.7% were fully vaccinated. These vaccination estimates will differ from daily official government figures, which are actual numbers of vaccines recorded.
Last updated: 16/09/2021
Trends in antibody positivity are similar across data sources
Estimated percentage of the community population testing positive for antibodies to SARS-CoV-2, 28 April 2020 to 24 September 2021, England
The proportion of people aged 16 years and over testing positive for COVID-19 antibodies in England increased between December 2020 and August 2021. The Coronavirus Infection Survey (CIS), UK Health Security Agency (formerly Public Health England) data from NHS Blood and Transplant (NHS-BT) blood donors, and Real-time Assessment of Community Transmission-2 (REACT-2) show similar trends in antibody positivity.
Overall REACT-2 estimates are slightly lower, which could be because the REACT-2 test is self-administered, whilst CIS and NHS-BT tests involve blood samples taken by a health professional. While all figures are adjusted in attempt to represent the population, CIS and REACT test randomly selected people and NHS-BT estimates are based on results from healthy adult blood donors. Additionally, each source reports data for different time periods: NHS-BT estimates are four-week averages, CIS figures are weekly estimates and REACT-2 reports results for testing rounds lasting between 14 and 24 days.
Last updated: 08/10/2021
Over a quarter of school staff had antibodies against COVID-19 from past infection
Percentage of staff testing positive for COVID-19 antibodies in primary and secondary schools, 3 to 20 November 2020 (Round 1), 30 November to 11 December 2020 (Round 2), 15 to 31 March 2021 (Round 4), 5 to 21 May 2021 (Round 5) and 14 June to 6 July 2021 (Round 6), England
The percentage of staff testing positive for COVID-19 antibodies continued to increase, for both primary school and secondary school staff between Round 5 (5 to 21 May 2021) and Round 6 (14 June to 6 July 2021). The antibody test used in this study detects antibodies produced following an infection and not vaccination. By the end of June 2021, 92.93% of staff had received at least one dose of a COVID-19 vaccine and 70.47% had received both doses.
You can read more about antibody testing in different surveys on our more information page. Caution is needed when interpreting these results as they are not intended to be generally applicable to all schools in England.
Last updated: 11/08/2021
COVID-19 antibody positivity is increasing among those aged 16 to 24 years and remains high for all other age groups across the UK
Modelled percentage of adults who tested positive for antibodies to SARS-CoV-2, who have received one or more doses of a COVID-19 vaccine, and who were fully vaccinated; by grouped age, UK countries, 7 December 2020 to 29 August 2021
In the week beginning 23 August 2021, the percentage of adults testing positive for antibodies increased or remained high for all age groups. Antibody positivity for those aged 16 to 24 years is increasing steadily across all four UK countries, with estimates ranging between 86.9% and 88.7%. Antibody positivity remains very high in older age groups (those aged 65 years and above) but has remained level or declined slightly since the end of July 2021. This means that some people in these groups did not have enough antibodies to be detected in the test, not that they do not have any immune protection against the virus. Please read our Antibodies and Immunity blog for more information.
Across the four UK countries, the estimated percentage of adults aged 25 to 34 years who have received one or more doses of COVID-19 vaccine ranged from 86.9% to 91.4%. This has increased sharply since the end of May. A similar increase can be seen for those aged 16 to 24 years since June, with between 70.8% and 78.8% having received at least one dose of a COVID-19 vaccine in the week beginning 23 August 2021.
Last updated: 16/09/2021
Percentages testing positive for COVID-19 antibodies by single year of age
Modelled percentage of adults testing positive for antibodies to SARS-CoV-2, by single year of age, UK countries, 5 July to 23 August 2021
Antibody positivity increased or remains high for most age groups in England, Wales, Northern Ireland and Scotland. There was a decrease in antibody positivity in the older age groups. This does not mean that these older people have no immune protection, as is explained in our Antibodies and Immunity blog.
We can examine the changes in antibody positivity over shorter periods by using modelled daily estimates, presented in this graphic. The method used to generate the data differs slightly to the weekly modelled estimates of antibody positivity, so they are not comparable.
Last updated: 16/09/2021
The Coronavirus (COVID-19) Infection Survey (CIS) estimates antibody positivity based on blood test results taken from a randomly selected subsample of individuals aged 16 years and over in England, Wales, Northern Ireland and Scotland. The REACT-2 study tests randomly selected participants aged 18 years and over from the NHS patient list in England, who self-administer a lateral flow immunoassay (LFIA) finger prick test to detect antibodies against SARS-CoV-2. The UK Health Security Agency (formerly Public Health England) publishes antibody positivity based on testing samples from healthy adult blood donors aged 17 years and older, supplied by NHS Blood and Transplant (NHS BT) as part of the UKHSA sero-surveillance programme. Antibody data from CIS, REACT-2 and UKHSA, that is presented on our tool includes antibodies from both infections and vaccinations.
The Coronavirus Schools Infection Survey estimates the percentage of staff and pupils with antibodies against COVID-19. Staff are tested from blood and pupils from oral-fluid samples using assays that detect antibodies from a previous infection, but not from vaccination.
To find out more about antibody data from different sources visit our more information page.