LC infections over time

A model based on data provided from the Canadian government suggests that nearly every child may experience Long COVID symptoms by age 10, driven by recurrent COVID-19 infections and cumulative risk.

1. Long COVID Risk per Infection
2. Risk estimates:
   • 13% after the first infection
   • 23% cumulative after a second infection
   • 37% cumulative after a third infection

3. Source: Institut national de santé publique du Québec

4. Increased Risk with Re-infections

5. Statistics Canada findings:
   • Canadians with one infection: 14.6% reported prolonged symptoms
   • Canadians with two infections: 25.4% (1.7 times higher risk than one infection)
   • Canadians with three or more infections: 37.9% (2.6 times higher risk than one infection)
6. Source: Statistics Canada

This model, developed by analyzing infection rates and using data from the Institut national de santé publique du Québec and the COVID-19 Immunity Task Force, estimates an average infection rate of once per person per year. With each infection presenting a 13% risk of developing Long COVID, repeated exposures drastically increase cumulative risk over time.

Key findings from the model:

• 2022: After the first infection, each individual faces a 13% risk of Long COVID.
• 2026: With five infections, the risk climbs to approximately 50%.
• 2032: After ten infections, the risk reaches around 78%.

The methodology uses a cumulative risk formula to calculate the likelihood of developing Long COVID over multiple infections, assuming infections occur independently and at a constant risk rate. The model estimates that nearly all children will face Long COVID by age 10 if these infection rates continue, potentially marking a significant long-term health impact for the entire population.

To explore the data and methodology behind these findings, you can view the project and code on GitHub: LC-Risk Estimator.

The Long COVID Risk

The most severe potential outcome of Long COVID involves several interconnected risks that could create a downward spiral of health and economic consequences:

The global burden could exceed 400 million cases by late 2023, with numbers continuing to grow due to reinfections and new variants. This estimate is likely conservative as it doesn't account for asymptomatic infections.

The condition remains poorly understood, with multiple proposed mechanisms including viral persistence, immune dysregulation, and mitochondrial dysfunction. Limited research funding and lack of standardized diagnostic tools hinder treatment development. Without clear understanding of its subtypes, developing targeted therapies remains difficult.

Studies show concerning low recovery rates, with many cases potentially becoming chronic conditions. A significant portion of affected individuals experience reduced work capacity or complete disability, leading to long-term dependence on support systems.

The estimated annual global cost could reach $1 trillion through:

• Reduced workforce participation

• Increased healthcare costs

• Lost productivity

• Strain on public finances

• Potential labor shortages

• Social and Development Impact

Marginalized communities face disproportionate effects and barriers to care

Progress toward Sustainable Development Goals could be undermined

Existing health inequalities may worsen

Access to healthcare and poverty reduction efforts could be reversed

Without effective prevention and treatment strategies, this scenario could result in a significant portion of the population facing chronic illness and disability. The cascading effects would impact all aspects of society, creating a future marked by widespread health challenges and economic hardship.

Recent surges in pneumonia and other respiratory illnesses in the U.S. may be linked to immune system damage from repeated COVID-19 infections and Long COVID (LC). Mycoplasma pneumoniae, a common cause of "walking pneumonia," has sharply increased among children, alongside significant rises in hospitalizations for COVID-19, influenza, and RSV​.

Research reveals that LC often weakens immune response, leaving individuals more vulnerable to additional infections. Autoimmune responses triggered by LC can create chronic inflammation, damaging lung and other body tissues. This impaired immunity is thought to be a factor behind severe respiratory outcomes, including recurrent pneumonia, as the immune system becomes less capable of fighting off routine pathogens.

With cumulative COVID exposure, especially in young people, the weakened immune systems may struggle to fend off infections. Preventive health measures and managing LC risks are critical to mitigating these rising respiratory threats.

The urgent need for measures to reduce transmission and manage Long COVID risks as COVID continues to circulate globally.