Long Covid: Reviewing the science and assessing the risk (5 October 2020)

Summary

'Long Covid' is a term is used to describe individuals who continue to suffer from COVID-19 symptoms outside of the two-week period in which they are believed to be infected. The World Health Organization (WHO) endorsed this two-week period as enough time for the virus and its symptoms to be able to come and go, yet studies are revealing cases in which symptoms are persisting well outside of this window. Survivors may have a chronic debilitating illness for many months.

Content

The Covid Symptom Study led by King’s College London, underpinned by a self-reporting app from health-science company ZOE, has involved more than 4 million users in the UK and is being used to track and monitor COVID-19 symptoms over time. Researchers have used this data since 24 March to study the patterns and duration of COVID-19 symptoms.

In this paper from the Tony Blair Institute for Global Change, combined data from the King's College London Covid Symptom Study with emerging evidence from the broader scientific community to understand what we do and – as importantly – don’t know about those suffering with long-term symptoms of COVID-19. The Covid Symptom Study is unique as it has one of the largest sample sizes of COVID-19 studies with more than 4 million participants, but it is important to note that the data is collected and analysed based on self-reported symptoms recorded through an app. New findings from the study, which will be published in full by King’s College later this month, indicate that around 10% of those taking part in the survey had symptoms of long Covid for a month, with between 1.5% and 2% still experiencing them after three months.

Extrapolating from this, the researchers believe that of those affected by the first wave of the virus in the UK, 300,000 people would have had Covid symptoms for a month and 60,000 for three months or more. Properly understanding the scope and scale of the issue of long Covid is critical in both communicating and balancing the overall risk of the virus, particularly as governments determine their next steps in containing COVID-19 and avoiding a full lockdown.