People with weakened immune systems (the immunosuppressed) are more likely to get severely ill with respiratory diseases like COVID-19 or struggle with long-term health problems afterwards. Even when vaccinated, these patients may not be able to fight off these infections and, as a result, may not be as protected from critical outcomes as others. For these patients, the pandemic is still very much ongoing.  

However, we still don’t know enough about how these risks differ between types of immunosuppressed patients. Our ability to investigate this has been affected by the lack of standardisation in how immunosuppression is defined and subdivided. This investigation therefore plans to take an expert-approved classification and use it to identify the immunosuppressed in the ORCHID-E primary care database and divide these patients into subgroups and risk categories. We will then assess whether numbers of COVID-19 infection and negative follow-on events – including respiratory infections (pneumonia, bronchitis etc.), blood clots, heart failure, Long COVID and mortality – significantly differ between these subgroups and risk categories. We anticipate that we will see greater numbers of these events amongst those with conditions categorised as higher risk than those with conditions categorised as lower risk. 

We hope that by doing this research we can understand which immunosuppressed populations need more support in terms of COVID-19 prevention and response. This may involve prioritising those seen to be at greatest risk for special resources such as additional vaccine doses, monoclonal antibodies and convalescent plasma.