Fortress Fast COVID-19 anti-body test, containing test kit in a box, Ipsos MORI headed paper reading ‘with compliments’, instruction booklet, information sheet for participants, and sheet of additional information, produced as part of the Real-time Assessment of Community Transmission (REACT-2) study conducted by Imperial College London and the polling company Ipsos Mori, UK, 2021

In a pandemic, a major challenge for scientists is to track how disease is spreading and how many people have been infected. Between July 2020 and May 2021, more than 900,000 people got involved in the REACT-2 study by completing an at home COVID-19 antibody test.

Before they could roll out the large-scale programme in July 2020, scientists had to make sure people were willing to do the test and that it was accurate enough. Unlike many COVID-19 tests, these antibody tests used blood samples and required people to prick their finger. Rather than looking for signs of a current infection, an antibody test is looking for signs that you’ve had an immune response to COVID-19. Initially, this would have come from being infected with COVID-19. But since the vaccine rollout began, it can also detect the antibodies someone has produced after being vaccinated.