A UCL study found that 70% of young people with long Covid recovered within 24 months, but recovery was less likely among older teenagers, females, and those from deprived backgrounds. Researchers emphasized the need for further investigation and collaboration to address unresolved cases.
A new study led by UCL researchers reveals that most young individuals diagnosed with long Covid three months after a positive PCR test had fully recovered within 24 months.
The Children and young people with Long Covid (CLoCK) study, published in Nature Communications Medicine and funded by the National Institute for Health and Care Research (NIHR), is the world’s largest longitudinal cohort study on long Covid in children.
The researchers, led by Professor Sir Terence Stephenson and Professor Roz Shafran (both UCL Great Ormond Street Institute of Child Health), asked young people aged 11 to 17 about their health three, six, 12 and 24 months after taking a PCR test for the Covid virus between September 2020 and March 2021. They also asked them to recall their symptoms at the time of taking the test.
In February 2022, the researchers published a consensus definition of long Covid which involved a young person having more than one symptom (such as tiredness, trouble sleeping, shortness of breath or headaches) alongside problems with either mobility, self-care, doing usual activities, having pain/discomfort, or feeling very worried or sad.
The researchers used this definition for their new study, which examined data from 12,632 young people who had a PCR test for SARS-CoV-2 (the virus that causes COVID-19). They found that around 25-30% of young people met the research definition of long Covid 24 months after their initial PCR test.
Study Results: Recovery Trends
Of the 12,632 young people in total, there were 943 who had tested positive when first approached and who provided answers at every time point: three, six, 12 and 24 months after their original test.
Of these 943 young people, 233 met the research definition of long Covid three months after their initial positive test. At six months,135 continued to meet the research definition of long Covid. At 12 months, 94 continued to fulfill the long Covid research definition.
However, only 68 of these 943 children and young people (7.2%) continued to fulfill the long Covid research definition when contacted 24 months after their initial positive test.
This means that 24 months after a proven Covid infection, 165 of the 233 young people (70%) who had long Covid three months after the infection and provided information at every time point in the research had recovered. But 68 of the 233 (30%) had not.
Key Demographic Findings
Older teenagers and the most deprived were less likely to have recovered. And, strikingly, females were almost twice as likely to still meet the research definition of long Covid at 24 months, compared to males.
However, the researchers note that they did not assess menstruation and some symptoms (such as headaches and tiredness) may be attributable to pre-menstrual syndrome given the high proportion of girls.
Study Chief Investigator and first author, Professor Sir Terence Stephenson, said: “Our findings show that for teenagers who fulfilled our research definition of long Covid three months after a positive test for the Covid virus, the majority have recovered after two years. This is good news but we intend to do further research to try to better understand why 68 teenagers had not recovered.”
The CLoCK study is a major study funded by the National Institute for Health and Care Research (NIHR) and UK Research and Innovation (UKRI) to help improve understanding of the causes, symptoms, and treatment of the longer-term effects of Covid-19 in people who have not become unwell enough to be admitted to hospital.
The study was co-led by the UK Health Security Agency (UKHSA) in collaboration with researchers at Great Ormond Street Hospital for Children NHS Foundation Trust (GOSH), Imperial College London, King’s College London, Manchester University NHS Foundation Trust, the Universities of Bristol, Cambridge, Edinburgh, Liverpool, Manchester and Oxford, and University College London Hospitals NHS Foundation Trust. CLoCK also works closely with a patient and public involvement advisory group.
Following the 24-month results, data from all time points are now publicly available to other researchers.
The UCL researchers recently published a commentary, alongside colleagues at GOSH and the University of Brighton, on why better collaboration is needed between clinicians, interventionalists, epidemiologists, statisticians and those with lived experience to ensure a more effective, coordinated response ahead of future pandemics.
Study limitations
The symptoms reported by participants at the time of testing are subject to recall bias as they were reported at the time of first contact with the CLoCK study. However, three-month, six-month, 12-month, and 24-month symptoms were reported at the time they were being experienced.
Of the 31,012 children and young people invited to fill in a questionnaire 24-months post-PCR test, 12,632 of them participated and so this is a self-selected group which may introduce bias in the results.
Original PCR tests were taken before the Delta and Omicron variants became dominant, so the findings may not reflect the long-term effects of these variants.
Children and young people self-reported their symptoms. In some instances, such as to assess shortness of breath, it may have been better to conduct in-person medical interviews. However, this was not feasible or practical during the study period.
Importantly, the study primarily focuses on children and young people in England, and the findings may not be directly applicable to other populations or countries with different healthcare systems, vaccination rates, and demographics.
Reference: “A 24-month National Cohort Study examining long-term effects of COVID-19 in children and young people” by Terence Stephenson, Snehal M. Pinto Pereira, Manjula D. Nugawela, Emma Dalrymple, Anthony Harnden, Elizabeth Whittaker, Isobel Heyman, Tamsin Ford, Terry Segal, Trudie Chalder, Shamez N. Ladhani, Kelsey McOwat, Ruth Simmons, Laila Xu, Lana Fox-Smith, CLoCk Consortium and Roz Shafran, 4 December 2024, Communications Medicine.
DOI: 10.1038/s43856-024-00657-x

News
Breakthrough for long Covid patients who lost sense of smell
A breakthrough nasal surgery has restored the sense of smell for a dozen long Covid patients. Experts at University College London Hospitals NHS Foundation Trust successfully employed a technique typically used for correcting blocked nasal passages, [...]
Scientists Invent Plastic That Can Dissolve In Seawater In Just A Few Hours
Plastic waste and pollution in the sea have been among the most serious environmental problems for decades, causing immense damage to marine life and ecosystems. However, a breakthrough discovery may offer a game-changing solution. [...]
Muscles from the 3D printer
Swiss researchers have developed a method for printing artificial muscles out of silicone. In the future, these could be used on both humans and robots. Swiss researchers have succeeded in printing artificial muscles out [...]
Beneficial genetic changes observed in regular blood donors
Researchers at the Francis Crick Institute have identified genetic changes in blood stem cells from frequent blood donors that support the production of new, non-cancerous cells. Understanding the differences in the mutations that accumulate [...]
Shocking Amounts of Microplastics in the Brain – It Could Be Increasing Our Risk of Dementia
The brain has higher concentrations of plastic particles compared to other organs, with increased levels found in dementia patients. In a comprehensive commentary published in Brain Medicine, researchers highlight alarming new evidence of microplastic accumulation [...]
Baffling Scientists for Centuries: New Study Unravels Mystery of Static Electricity
ISTA physicists demonstrate that contact electrification depends on the contact history of materials. For centuries, static electricity has intrigued and perplexed scientists. Now, researchers from the Waitukaitis group at the Institute of Science and [...]
Tumor “Stickiness” – Scientists Develop Potential New Way To Predict Cancer’s Spread
UC San Diego researchers have developed a device that predicts breast cancer aggressiveness by measuring tumor cell adhesion. Weakly adherent cells indicate a higher risk of metastasis, especially in early-stage DCIS. This innovation could [...]
Scientists Just Watched Atoms Move for the First Time Using AI
Scientists have developed a groundbreaking AI-driven technique that reveals the hidden movements of nanoparticles, essential in materials science, pharmaceuticals, and electronics. By integrating artificial intelligence with electron microscopy, researchers can now visualize atomic-level changes that were [...]
Scientists Sound Alarm: “Safe” Antibiotic Has Led to an Almost Untreatable Superbug
A recent study reveals that an antibiotic used for liver disease patients may increase their risk of contracting a dangerous superbug. An international team of researchers has discovered that rifaximin, a commonly prescribed antibiotic [...]
Scientists Discover Natural Compound That Stops Cancer Progression
A discovery led by OHSU was made possible by years of study conducted by University of Portland undergraduates. Scientists have discovered a natural compound that can halt a key process involved in the progression [...]
Scientists Just Discovered an RNA That Repairs DNA Damage – And It’s a Game-Changer
Our DNA is constantly under threat — from cell division errors to external factors like sunlight and smoking. Fortunately, cells have intricate repair mechanisms to counteract this damage. Scientists have uncovered a surprising role played by [...]
What Scientists Just Discovered About COVID-19’s Hidden Death Toll
COVID-19 didn’t just claim lives directly—it reshaped mortality patterns worldwide. A major international study found that life expectancy plummeted across most of the 24 analyzed countries, with additional deaths from cardiovascular disease, substance abuse, and mental [...]
Self-Propelled Nanoparticles Improve Immunotherapy for Non-Invasive Bladder Cancer
A study led by Pohang University of Science and Technology (POSTECH) and the Institute for Bioengineering of Catalonia (IBEC) in South Korea details the creation of urea-powered nanomotors that enhance immunotherapy for bladder cancer. The nanomotors [...]
Scientists Develop New System That Produces Drinking Water From Thin Air
UT Austin researchers have developed a biodegradable, biomass-based hydrogel that efficiently extracts drinkable water from the air, offering a scalable, sustainable solution for water access in off-grid communities, emergency relief, and agriculture. Discarded food [...]
AI Unveils Hidden Nanoparticles – A Breakthrough in Early Disease Detection
Deep Nanometry (DNM) is an innovative technique combining high-speed optical detection with AI-driven noise reduction, allowing researchers to find rare nanoparticles like extracellular vesicles (EVs). Since EVs play a role in disease detection, DNM [...]
Inhalable nanoparticles could help treat chronic lung disease
Nanoparticles designed to release antibiotics deep inside the lungs reduced inflammation and improved lung function in mice with symptoms of chronic obstructive pulmonary disease By Grace Wade Delivering medication to the lungs with inhalable nanoparticles [...]