Most young individuals diagnosed with long Covid three months after a positive PCR test showed signs of recovery within two years, according to a recent study.
A recent study led by researchers at UCL found that most young individuals diagnosed with long Covid three months after a positive PCR test recovered within 24 months.
The Children and Young People with Long Covid (CLoCK) study, published in Nature Communications Medicine and backed by the National Institute for Health and Care Research (NIHR), stands as the largest longitudinal cohort study on long Covid in children worldwide.
Researchers, under the direction of Professor Sir Terence Stephenson and Professor Roz Shafran from the UCL Great Ormond Street Institute of Child Health, surveyed young individuals aged 11 to 17 on their health status three, six, 12, and 24 months post-PCR testing for the Covid virus between September 2020 and March 2021. They also requested participants to recall their symptoms when they took the test.
In February 2022, the team established a consensus definition of long Covid, which indicates that a young person must experience more than one symptom (like fatigue, difficulty sleeping, breathlessness, or headaches) in addition to challenges with mobility, self-care, daily activities, pain/discomfort, or significant feelings of worry or sadness.
This definition was employed in their latest research, which analyzed data from 12,632 young people who underwent a PCR test for SARS-CoV-2 (the virus responsible for Covid-19). The study revealed that around 25-30% of these youths met the criteria for long Covid two years after their initial PCR test.
Out of the total of 12,632 young individuals, 943 tested positive when first contacted and provided answers at each time interval: three, six, 12, and 24 months after their original test.
From these 943 youths, 233 were identified as having long Covid three months following their positive test. By six months, 135 of them still met the criteria for long Covid, and at 12 months, 94 continued to meet the long Covid definition.
However, at the 24-month mark, only 68 of the 943 children and adolescents (7.2%) continued to satisfy the criteria for long Covid based on research definitions.
This indicates that 24 months following a confirmed Covid infection, 165 out of the 233 young individuals (70%) who were diagnosed with long Covid three months post-infection and provided consistent information throughout the study had recovered. Conversely, 68 of the 233 (30%) had not yet recovered.
Older teenagers and those in financially disadvantaged situations were less likely to have fully recovered. Notably, females were nearly twice as likely to still meet the criteria for long Covid at 24 months compared to their male counterparts.
However, the researchers mentioned that they did not examine menstrual cycles, and certain symptoms (like headaches and tiredness) could be linked to pre-menstrual syndrome given the significant number of female participants.
Professor Sir Terence Stephenson, the main investigator and lead author of the study, commented: “Our results indicate that the majority of teenagers who met our long Covid criteria three months after a positive Covid test have recovered by the two-year mark. This is reassuring, but we plan to conduct further research to understand why 68 adolescents have not fully recovered.”
The CLoCK study is a significant initiative funded by the National Institute for Health and Care Research (NIHR) and UK Research and Innovation (UKRI), aimed at enhancing understanding of the causes, symptoms, and treatments related to the long-term effects of Covid-19 in individuals who have not been hospitalized.
This study was co-led by the UK Health Security Agency (UKHSA) in partnership with researchers from Great Ormond Street Hospital for Children NHS Foundation Trust (GOSH), Imperial College London, King’s College London, Manchester University NHS Foundation Trust, and the Universities of Bristol, Cambridge, Edinburgh, Liverpool, Manchester, Oxford, as well as University College London Hospitals NHS Foundation Trust. CLoCK also collaborates closely with a patient and public involvement advisory group.
Following the release of the 24-month results, data from all time points are now accessible for other researchers.
The UCL team has recently published a commentary, alongside colleagues from GOSH and the University of Brighton, emphasizing the importance of improved collaboration among clinicians, interventionalists, epidemiologists, statisticians, and those with personal experiences to ensure a more coordinated response to future pandemics.
Study Limitations
The symptoms reported by participants at the testing time may be influenced by recall bias, as they were documented during initial contact with the CLoCK study. Nevertheless, symptoms at three, six, 12, and 24 months were recorded as they were being experienced.
Out of the 31,012 children and adolescents invited to complete a questionnaire 24 months post-PCR test, 12,632 participated, leading to a self-selected group that might introduce bias in the results.
The initial PCR tests occurred before the Delta and Omicron variants became prevalent, which may mean that the results do not reflect the long-term impacts of these variants.
Children and adolescents self-reported their symptoms. For assessing issues like breath shortness, direct medical interviews might have been more effective. However, this was not practical during the study.
It’s essential to note that the focus of the study was primarily on young individuals in England, and the findings may not be directly applicable to other communities or nations with different healthcare structures, vaccination rates, and demographic profiles.
