The research studies, backed by the COVID symptom study app, are starting to develop a picture of who is at risk of developing Long COVID. A team from King's College London, England, and led by Professor Tim Spector, has identified potentially six clusters of factors during the first week of illness which may be associated with increased risk of Long COVID: people having a persistent cough, a hoarse voice and sore throat, headache, diarrhoea, skipping meals or feeling shortness of breath during their first week of the illness appear more likely to get long term symptoms.