To stop the spread of COVID-19, we needed to better understand how it spreads at home, work, school and other public places and if this changes by age, ethnic background, time or location.  

The Race Equality Foundation and Doctors of the World advised us on how best to include people from minority ethnic backgrounds in the Virus Watch study. Together we set up an advisory group, which included lay members. Our advisory group helped us decide how to recruit people to our research study as well as analyse our data and understand it better. They also helped us decide how best to share our findings with different groups of people. 

Our research project used data from Virus Watch, a large community study of over 50,000 children and adults, which used finger-prick antibody tests and PCR or lateral flow tests to find out if people were infected with COVID-19 during the 2020/21 winter wave of the COVID-19 pandemic. 

Using this information we determined how the risk of catching infection outside the household was related to activities outside their homes and found that the risk of infection was strongly connected to the number of people our study participants were in close contact with.   

We learned that people working outside of their homes increased their risk of catching COVID-19 by about 20% than those who didn’t and that using public or shared transport and how often people went to the shops were important risk factors for catching COVID-19. 

The restrictions during the 2020/21 winter wave meant that people were rarely leaving home for other activities such as going to parties, cinemas, theatres, restaurants and pubs so these were not important causes of spreading COVID 19. Most people in our study were working from home or not using public transport but most were regularly shopping for essential items. Because of this, shopping caused a higher proportion of cases than either going to work or using public transport. 

We also used data from the very large (over 450,000 participants) Office for National Statistics COVID-19 Infection Survey that regularly tested participants for COVID-19, using PCR tests. By analysing data on those who took part in the survey between 26th April 2020 and 4th October 2021, we found  that risk of infection appeared to be  related to the number of close contacts people had, leaving home for work, use of public transport and having visitors to their houses, though patterns varied over time 

Although differences in how COVID-19 infections were identified and the questions asked in the different surveys mean the results cannot be perfectly compared, we were still able to show that leaving home for work, using public transport and coming into close contact with others were in important risk factors for spreading COVID-19.