Reinfection Considerably Increases Long COVID Risk in Children
New research published in The Lancet Infectious Diseases (September 2025) highlights a concerning trend: reinfection with SARS-CoV-2 more than doubles a child’s risk of developing post-acute sequelae of SARS-CoV-2 infection (PASC), commonly known as long COVID.
The study estimates an incidence rate of 904 cases of long COVID per million children following a primary infection. This rate more than doubled to 1884 per million after a subsequent infection. researchers found that reinfection was associated with an adjusted hazard ratio (aHR) exceeding 2.0 for long COVID compared to initial infection, a connection that remained notable even after accounting for factors like age, sex, race/ethnicity, vaccination status, pre-existing health conditions (including overweight/obesity), and the severity of the initial illness.
Importantly, this increased risk was observed consistently across all demographic and clinical subgroups analyzed.
Reinfection was linked to a variety of health issues, including myocarditis, thromboembolic events, acute kidney injury, neurocognitive difficulties, persistent fatigue, and respiratory impairment. While the absolute risk of these outcomes remains low, the potential for serious complications is a cause for concern, according to the study authors.
The findings suggest a cumulative risk of long COVID with each successive infection, aligning with evidence indicating waning immunity post-infection. While T-cell responses appear stable, neutralizing antibody levels decline over time, potentially reducing protection against reinfection. This is particularly relevant given the rapid decline in protection observed during the Omicron era,which saw increased reinfections,especially among young adults aged 18-49.
Previous pediatric studies have identified clinical markers of long COVID in children, including specific proteomic biosignatures, Postural Orthostatic Tachycardia Syndrome (POTS), exercise intolerance, vascular problems, and central nervous system (CNS) issues.This new research reinforces these findings by demonstrating the persistence of post-acute sequelae across multiple infections and the ongoing clinical burden they represent.
Despite not guaranteeing complete protection, COVID-19 vaccines remain the most effective strategy for reducing both primary and repeat infections, and consequently, the risk of long COVID in children. The researchers emphasize the importance of intensifying vaccination efforts and maintaining layered public health measures, particularly in areas with high transmission rates.
The RECOVER Initiative is continuing to investigate the long-term effects, risk factors, and underlying mechanisms of long COVID to inform preventative strategies and develop effective treatments for both children and adults.
Data from the National Notifiable Disease Surveillance System shows 163,261 confirmed COVID-19 cases reported in Australia so far this year (as of October 8, 2025), with 30,926 cases occurring in individuals aged 19 years and younger.The 0-4 year age group accounts for the majority of these cases (15,821). In 2024,a total of 341,840 COVID-19 cases were reported,including 52,588 among those 19 and under,with nearly half (25,357) in the 0-4 age bracket.
