Flu can cause similar long-term symptoms to Covid, a study suggests.
Patients hospitalised with either seasonal flu or Covid were both at greater risk of dying over the following 18 months.
Respiratory problems were most common, with patients more likely to be readmitted to hospital if they had suffered either condition.
Experts said it showed the importance of annual jabs, particularly in the elderly and most vulnerable.
A major lesson learned from Covid was that an infection that initially was thought to only cause brief illness also can lead to chronic disease.
Covid was initially thought to only cause brief illness but was discovered to also lead to chronic disease. Researchers from Washington University looked at whether the same was true for flu (Stock Image)
Although Covid showed a greater risk of health loss than seasonal influenza, infection with either virus carried significant risk of disability and disease (Stock Image)
This spurred researchers from Washington University School of Medicine to look at long-term outcomes of Covid alongside flu.
They analysed more than 90,000 records of patients up to 18 months post-infection with either virus, comparing the risks of death, hospital admissions and 94 adverse health outcomes involving the body’s major organ systems.
The highest risk was 30 days after the initial infection for both conditions, according to the findings published in the Lancet.
Although Covid showed a greater risk of health loss than seasonal influenza, infection with either virus carried significant risk of disability and disease.
Covid patients had an increased risk of 68 per cent of health conditions examined across all organ systems, compared to 6 per cent with the flu – which occurred mostly in the respiratory system.
Ziyad Al-Aly, a clinical epidemiologist at Washington University, said: ‘Many people think they’re over Covid or the flu after being discharged from the hospital.
‘That may be true for some people. But our research shows that both viruses can cause long-haul illness.’
He added: ‘For both Covid and seasonal influenza, vaccinations can help prevent severe disease and reduce the risk of hospitalizations and death.
‘Optimizing vaccination uptake must remain a priority for governments and health systems everywhere. This is especially important for vulnerable populations such as the elderly and people who are immunocompromised.’