PERSISTENT symptoms following childhood respiratory infections vary according to both the virus and the age of the child, new research suggests.
A direct comparison of SARS-CoV-2, respiratory syncytial virus and influenza found that the overall prevalence of post-acute symptoms was similar, but their clinical presentation differed markedly.
Researchers conducted a retrospective cohort study of children with laboratory-confirmed SARS-CoV-2, respiratory syncytial virus, or influenza infection.
Persistent symptoms after the acute stage were compared across the three groups. The analysis also examined whether age, hospitalisation, hypoxaemia and other characteristics predicted post-acute illness.
Unlike research focused exclusively on long COVID, the study considered whether persistent morbidity also followed other common viral respiratory infections.
Although the overall frequency of post-acute symptoms was comparable across the three infections, each virus produced a distinct pattern.
Following respiratory syncytial virus infection, persistent morbidity was dominated by respiratory symptoms and feeding difficulties, particularly among young infants.
Children recovering from SARS-CoV-2 were more likely to experience neurocognitive and systemic complaints. These problems were most apparent among school-aged children.
Influenza was associated primarily with sustained systemic symptoms rather than the infant respiratory pattern seen after respiratory syncytial virus or the neurocognitive presentation associated with SARS-CoV-2.
The analysis identified a significant interaction between virus type and age, indicating that the effects of each infection differed across stages of childhood.
Hypoxaemia during the acute illness was the strongest predictor of persistent symptoms following respiratory syncytial virus, more than doubling the odds.
Among children with SARS-CoV-2, age above 6 years was associated with approximately twice the odds of post-acute symptoms. Hospitalisation was also an important predictor.
Sensitivity analysis using inverse probability weighting produced consistent results, supporting the stability of the principal findings.
The research indicates that persistent illness is not unique to COVID-19 and that a single follow-up model may not adequately serve every child.
Infants recovering from severe respiratory syncytial virus may require particular attention to breathing and feeding, while older children recovering from COVID-19 may need assessment for fatigue, neurocognitive or broader systemic complaints.
Nevertheless, the retrospective design means the study depended on previously recorded symptoms and could not eliminate residual confounding. The findings should not be interpreted as showing that one virus universally causes more severe long-term illness than another.
Prospective studies with standardised symptom assessment will be needed to confirm the patterns and determine how they should influence paediatric follow-up.
Bedir F et al. Post-acute symptom persistence following SARS-CoV-2, RSV, and influenza in children: a retrospective cohort study. Medicine. 2026;105(37):e50497.
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