Long Covid Newsletter
Issue #38May 25, 20267 studies

84% of kids with long COVID still had symptoms 3.5 years after infection

This week brought major insights into long COVID's persistence, treatment possibilities, and the biological mechanisms driving symptoms that can last for years.

🧬 Children's Long COVID Persists for Years

  • 50 children and teens were followed for 3.5 years after their initial COVID infection, with 42 (84%) still meeting long COVID criteria
  • All 42 participants reported tiredness, while 34 (81%) experienced 5 or more ongoing symptoms
  • Qualitative interviews revealed that fatigue remained the central symptom, alongside co-occurring issues that significantly disrupted daily life, education, and social activities

Why it matters: This provides some of the longest follow-up data on pediatric long COVID, showing that symptoms can persist far longer than many expected and continue to significantly impact young people's lives.

🎖️ Top 10% journal 🔗 BMC public health Journal Article 🗓️ May 20

Key Findings

🧠 Brain Scans Link Cognitive Problems to Vascular Changes

  • 36 long COVID patients underwent ultra-high resolution 7 Tesla MRI scans to measure perivascular spaces (fluid-filled areas around blood vessels in the brain)
  • Higher numbers of these spaces in frontal brain regions correlated with worse processing speed and executive function
  • Participants with anxiety and depression showed increased white matter volume, potentially reflecting inflammatory vulnerability
💡 Microscopic brain changes may help explain why long COVID patients struggle with thinking and processing speed.

💊 Experimental Treatment Shows Promise

  • 10 patients with neurological long COVID symptoms received C1-esterase inhibitor (a complement system regulator) in a crossover trial
  • Treatment was linked to lower inflammatory proteins like CRP and IL-6, plus increased levels of proteins involved in brain and blood vessel repair
  • Molecular changes persisted even after treatment ended, suggesting potential lasting effects on immune and vascular pathways
💡 Targeting the complement immune system could offer a new therapeutic approach for neurological long COVID symptoms.
Top 20% journal 🔗 Cellular and molecular neurobiology Journal Article 🗓️ May 19

🧬 Genetics May Predict Long COVID Risk

  • Analysis of 80,726 people across Denmark, Norway, and Iceland found genetic predisposition to certain mental health conditions increased long COVID odds
  • Those with genetic liability for neuroticism, depression, or ADHD had 30-45% higher odds of developing long COVID
  • The associations remained even after accounting for measured personality traits, suggesting shared biological pathways rather than just behavioral differences
💡 Genetic factors that influence mental health may also make some people more vulnerable to persistent post-COVID symptoms.
🥈 Top 2% journal 🔗 EClinicalMedicine Journal Article 🗓️ May 21

🔬 Three Distinct Long COVID Patterns Emerge

  • 511 people with confirmed long COVID were tracked over 12 months, revealing three distinct symptom burden clusters
  • The highest-burden group maintained 6 symptoms at 6-9 months, while moderate and lowest groups peaked at 3 and 1 symptoms respectively
  • Older age, female sex, mental health disorders, and immunodeficiency all increased odds of being in the highest-burden cluster
💡 Long COVID isn't one condition but appears to have distinct patterns that could guide personalized treatment approaches.
Top 20% journal 🔗 BMC infectious diseases Journal Article 🗓️ May 22

💉 Booster Timing Matters for Older Adults

  • 450 adults aged 60+ received different COVID vaccine schedules, with the third dose given 2-6 months after the second
  • Those getting a third booster within this timeframe showed significantly higher antibody levels (geometric mean titers of 57-59 vs 15-22 for two-dose groups)
  • The three-dose regimen was associated with lower risks of COVID symptoms and long COVID compared to two-dose schedules
💡 Optimal booster timing could help protect vulnerable older adults from both acute COVID and long-term complications.
🥉 Top 5% journal 🔗 Frontiers in immunology Randomized Controlled Trial 🗓️ May 18

🚬 Tobacco Users Show Impaired Recovery

  • Longitudinal study compared long COVID recovery in people with tobacco use disorder versus healthy controls over 12 months
  • While healthy controls showed clear improvement by 12 months, those with tobacco use disorder had persistent impairment in clinical and cognitive functioning
  • Recovery differences went beyond smoking exposure alone, suggesting tobacco dependence itself affects post-COVID healing processes
💡 Tobacco dependence may interfere with the body's ability to recover from long COVID, highlighting the need for integrated treatment approaches.
🎖️ Top 10% journal 🔗 Nicotine Tob Res Journal Article 🗓️ May 18

Implications

This week's research reveals long COVID as a complex, heterogeneous condition with distinct patterns and risk factors. The persistence of symptoms in children, identification of brain-based mechanisms, and potential genetic predictors all point toward long COVID being a serious, long-term health challenge requiring targeted interventions and personalized care approaches.

Studies in this issue

Primary sources used for this newsletter.

  1. Long-term symptoms after Covid-19 in children and young people 3.5 years later
    main storyBMC public health2026-05-20PMID 42157207
  2. Safety, immune response, and long COVID after inactivated COVID-19 vaccine boosters in older Chinese adults
    key findingFrontiers in immunology2026-05-18PMID 42148138
  3. Patterns of Long COVID Symptoms Over Time in a National Community Group
    key findingBMC infectious diseases2026-05-22PMID 42168930
  4. Different Long-Term Recovery from Long COVID in People Who Smoke Compared to Healthy Non-Smokers
    key findingNicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco2026-05-18PMID 42149980
  5. C1-esterase inhibitor treatment may change immune and blood vessel responses in long COVID with neurological symptoms
    key findingCellular and molecular neurobiology2026-05-19PMID 42156560
  6. Stronger brain scans show more fluid-filled spaces are linked to worse thinking skills in long COVID
    key findingmedRxiv : the preprint server for health sciences2026-05-18PMID 42145596
  7. Genetic risk for mental health conditions and personality traits linked to long COVID symptoms in three Nordic populations
    key findingEClinicalMedicine2026-05-21PMID 42163972

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