October 6, 2023

expert reaction to study looking at long-term symptoms after other acute respiratory infections (including the common cold) versus after COVID-19

A study published in eClinicalMedicine looks at long term symptoms associated with respiratory infections such as the common cold versus COVID-19. 

Prof Peter Openshaw, Professor of Experimental Medicine, Imperial College London, said:

“This study of over 10,000 adult (>15y, mostly older white female) community participants identified cases of acute respiratory infection (ARI) known due to SARS-CoV-2 (n=1,311), and ARI cases in which testing for SARS-CoV-2 infection was negative (n=472).  The study ran from May 2020 to Oct 2021, during which time pre-Alpha, Alpha and Delta variants of SARS-CoV-2 were circulating and highly prevalent.  Influenza was rare in this period due to lockdown, but some circulation of human rhinovirus/enterovirus continued.

“The study confirms that many people who had not yet been vaccinated against COVID-19 and developed symptomatic ARI during the pandemic were not fully recovered at the time of final follow up.  As severity increased, participants were more likely to report having long COVID, ranging from 5.9% in the mild class to nearly half of participants in the severe class.  In either group, symptoms were often present at follow up for at least 4 weeks, but up to 12 weeks.  This was the case especially if symptoms were severe (which they were in 21%), but the symptom profile was largely similar in both ARI study groups.  An exception to this was memory problems and loss of taste or smell, which was more frequent in those identified as SARS-CoV-2 infected.  The study relies on diagnostic tests to exclude SARS-CoV-2 infection, which are known not to be perfect.

“The study is important in showing that recovery from ARI may be slow regardless of cause, that people should expect a slow return to normality and not expect to immediately return to full activities immediately after an ARI from whatever cause.  The study does not show how many of those suffering from ARI go on to develop longer term debility.

“The term ‘long cold’ used in the press release should not belittle the very significant disability that some with Long COVID suffer.”

Dr David Strain, Clinical Senior Lecturer and Honorary Consultant, University of Exeter, said:

“Vivaldi et al have presented a very well conducted prospective review of residual symptoms after Covid 19, and after other non-Covid respiratory infections.  They demonstrated, at least in the short term, persistence of symptoms can be troubling not just after COVID-19 but after many other infections.

“Whilst in the first to explore this prospectively, this is not a new phenomenon.  Indeed, the Spanish flu epidemic in 1918-20 left many individuals with Encephalitis Lethargica that took decades to resolve (This was the subject matter for the Oliver Sachs book “The Awakenings” or depending on the audience the Robert DeNiro and Robin Williams film).  The concept of post viral illness is also well established.  Today in the UK, approximately 280,000 people are living with Myalgic Encephalomyelitis (ME, otherwise known as Chronic Fatigue Syndrome) many of whom report a rather benign initial viral illness as the trigger.

“A limitation of this study is that it only looks at symptoms at a single timepoints.  Whereas those involved in the COVIDENCE trial report symptoms lasting beyond 3 months and up to 2 years, many of those with ME/CFS have experienced their symptoms for decades.  In the absence of an understanding of the mechanisms or any diagnostic tests they have faced unprecedented stigma from society.  It is hoped that it will not be the legacy of today’s healthcare system, to leave these young and previously fit people behind.  This study will bring into focus the urgent need for further research into post viral syndromes, the risk factors and therefore routes to risk mitigation, diagnostic tests and potential treatments to help the quarter of a million plus in the UK and Millions worldwide who are suffering this terrible condition.”

Prof Paul Harrison, Professor of Psychiatry, University of Oxford, said:

“The study supports previous findings that long-term symptoms are common after respiratory infections in general, not just following COVID-19.  However, COVID-19 infection was associated with a higher risk of several complaints, including memory problems, suggesting that ‘brain fog’ may be particularly related to the SARS-CoV-2 virus.  A strength of the study is its prospective, UK population-based nature.  A weakness is the relatively small number of non-COVID-19 infection cases.”

‘Long-term symptom profiles after COVID-19 versus other acute respiratory infections (COVIDENCE UK): a population-based observational study’ by Giulia Vivaldi et al. was published in eClinicalMedicine at 09.00am UK time on Friday 6 October 2023. 

DOI: 10.1016/j.eclinm.2023.102251

Declared interests

Prof Peter Openshaw: “Peter Openshaw is a Co-Lead on the Coronavirus Clinical Characterisation Consortium (ISARIC-4C) and immunology lead on PHOSP-COVID (a UKRI MRC COVID-19 Rapid Response consortium studying Long COVID, led by Chris Brightling, Leicester).  He has been a member of scientific advisory committees and/or spoken at meetings organised by Janssen, Sanofi, Moderna, Seqirus, AstraZeneca and GSK.”

Dr David Strain: “Prof Strain is the Medical Advisor to Action for ME, Associate Prof of Cardiometabolic Health at the University of Exeter Medical School and Chair of the BMA Board of Science.  No Financial interests to declare.”

Prof Paul Harrison: “No conflicts (except prior work on this topic, which the authors cite).”