Major study gives new insights into lasting impacts of COVID-19 on UK population

Tens of thousands of people in England may have lasting symptoms from COVID-19 more than a year after infection, new analysis reveals.

The findings come from a representative sample of more than a quarter of a million people in England surveyed as part of the REACT study, who self-reported their symptoms and the impact of COVID-19 on their health and quality of life, and have been published in the journal Nature Communications.

The work, led by researchers at Imperial College London, finds that while the vast majority of people recovered from infection within two weeks, a significant proportion of the group (7.5%) reported persistent symptoms lasting 12 weeks or more (long COVID), and 5% reported symptoms lasting more than a year.

The most common lasting symptoms were mild fatigue, difficulty thinking or concentrating and joint pains. But other persistent symptoms reported included loss or change of sense of smell or taste, shortness of breath, severe fatigue, chest tightness or pain, and poor memory.

People were more likely to report symptoms for a long time after their initial infection if they were female, had severe initial symptoms, were infected earlier in the pandemic, or had pre-existing health conditions.

Some of these symptoms were also quite often reported by people who did not have previous COVID-19. However, mental health and health-related quality of life were worse among participants with ongoing persistent symptoms post-COVID compared with those who had never had COVID-19 or had recovered.

According to the researchers, the analysis provides a snapshot of the continued impact of COVID-19 in the UK. They highlight that while SARS-CoV-2 infections are typically short duration, a significant proportion of adults will continue to experience persistent illness (Long COVID) that in some cases may last for over a year or more. But they highlight that a sizeable proportion still fully recover after a prolonged period.

Professor Paul Elliott, Chair in Epidemiology and Public Health Medicine from the School of Public Health at Imperial College London, said, "Our latest findings from the REACT study offer further insights into the underlying factors which are associated with prolonged symptoms after initial COVID-19. We find that the variant of SARS-CoV-2 people are infected with, the initial severity of their symptoms, and whether they have pre-existing health conditions all have an impact on whether they will develop lasting symptoms."

In the latest analysis, the team collected follow up survey responses from 276,840 adults in England who registered for the REACT study. Of these, 59% reported testing positive for COVID-19 between 2020 and 2022.

Analysis shows the average duration of symptomatic illness was around 10 days, but one in 10 people in the study reported symptoms for more than four weeks, one in 13 for more than 12 weeks, and one in 20 for more than a year.

The analysis showed that almost a third of people reporting symptoms at 12 weeks will have recovered within a year. Among those whose lasting symptoms had fully resolved, people reported health status similar to those with shorter recovery, or who had never had COVID-19.

According to the researchers, analysis also shows that people infected in the omicron wave of the pandemic were 88% less likely to experience symptoms longer than four weeks post-infection, compared to earlier waves.

Dr. Christina Atchison, principal clinical academic fellow within the School of Public Health and first author on the study, said, "While the landscape has changed considerably since the early peak of the COVID-19 pandemic, this analysis shows that a proportion of adults are still experiencing lasting symptoms."

"Importantly, we find that compared to wild type virus, those infected when omicron was dominant were far less likely to report symptoms lasting beyond 12 weeks. This may reflect the changing levels of immunity in the population from previous exposure to the virus and vaccination."

Professor Helen Ward, from the School of Public Health at Imperial College London, said, "The study has shown some big variation in people's symptoms post-COVID. While we have gained valuable insights into the groups at risk of lasting symptoms, we are undertaking detailed interviews to further understand the variation in people's experiences and the impact on their everyday lives. We are also planning further follow-up of people involved in the REACT studies to assess the broader longer-term impact of the pandemic on health and well-being."