University of Liverpool

The immune system normally protects people from infection but could make COVID-19 worse. COVID-19 is likely to be around for a long time, so we need to know how long people are protected from re-infection and particularly if the immune system fails to protect some people. We are uniquely placed to do this. We have already obtained samples from 2,106 people with COVID-19; by analysing these we can find out if people’s immune systems are contributing to disease.

We will now also follow 400 survivors for 5 years to study:

  • Antibodies in the nose, mouth and circulation. These are sticky chemicals made by the body after it has dealt with an infection. They should protect us from future infection, but some people make better antibodies than others. Some people lose their antibodies quite quickly, and others as they age.
  • Immune memory cells These cells remember past viruses and accelerate protective responses to related viruses when encountered in the future, but some viruses make the immune system lose its memory.
  • Frontline immune defence cells (innate immunity). Some viral infections make the frontline immune cells overreact. This can drive severe disease and make people vulnerable to additional infections.
  • Future illness. We will use questionnaires and health records to better understand why some survivors suffer fatigue, new infections, or further COVID-19.

Understanding how the immune system behaves during and after COVID-19 will help to design treatments and inform government policy for vaccination, shielding, rehabilitation and other public health measures.