SARS-CoV-2 Neurological Impact On Human Species: Policy Perspective and Potential Crisis by 2045

Written By Tyler Fischella

Paper can be found here, undergoing edits.

Executive Brief:

As the world enters its fifth year of coexistence with COVID-19, emerging evidence suggests the pandemic's long-term toll may be neurological. While attention has rightfully focused on acute care for pulmonology and cardiology, death rates, and economic disruption, a slower, more insidious effect is unfolding in the background: a sustained, measurable neurological impact, driven by Long COVID and reinfection-related neuroinflammation.

Global population (2025): 8.1 billion

  • Estimated total infected by 2025: 6.5 billion

  • Long COVID rate: 20% of infected → 6.5B × 0.20 = 1.3 billion

  • Neurological symptom rate among Long COVID: 40% → 1.3B × 0.40 = 520 million (rounded to 600 million for modeling)

  • Severe neurological impairment rate: 15% of neurological cases → 600M × 0.15 = 90 million

  • IQ loss assumptions:

    • 85% mild impairment → 5-point loss

    • 15% severe impairment → 20-point loss

    • Average loss per case = (0.85 × 5) + (0.15 × 20) = 7.25 IQ points

  • Total IQ loss (2025): 600M × 7.25 = 4.35 billion IQ points

  • Cognitively active population (75% of global): 8.1B × 0.75 = 6.075 billion

  • Global IQ capacity (2025): 6.075B × 100 = 607.5 billion IQ points

  • Percent loss in 2025: 4.35B ÷ 607.5B = ~0.72%

This model begins with conservative estimates. As of 2025, approximately 6.5 billion people — or about 80% of the global population — have been infected with COVID-19 at least once. This estimate aligns with seroprevalence and statistical modeling by leading epidemiologists and global health organizations. For example, a 2022 Nature paper estimated global infections to exceed 60% by mid-2022, and a 2023 Lancet Infectious Diseases study projected 70–90% global exposure by early 2025 depending on regional transmission patterns.

Of those infected, studies show that approximately 10–30% develop Long COVID symptoms, with neurological complaints like brain fog, memory loss, and cognitive fatigue affecting roughly 30–50% of that subset. For example, research published in Nature Reviews Neurology (2023) and NIH data suggests that cognitive dysfunction is among the most common and persistent Long COVID sequelae, especially in working-age adults. A 2024 report from The Washington Post further confirms the prevalence of long-term cognitive effects, citing over 20 million cases in the U.S. alone with neurological symptoms.

An estimated 90 million individuals globally have experienced more severe impairment, consistent with dementia-like syndromes or moderate traumatic brain injury in terms of functional loss. Studies in Cell, The BMJ, and JAMA Neurology have highlighted structural brain changes post-infection, including gray matter loss, reduced cerebral blood flow, and evidence of persistent neuroinflammation.

Assume reinfection every 3 years per person

  1. Neurological risk per reinfection:

    • 2nd infection → 15%

    • 3rd+ infection → 50%

  2. Cumulative neuro cases by 2045: ~2.8 billion

  3. Total IQ points lost: 2.8B × 7.25 = 20.3 billion IQ points

  4. Projected population (2045): ~8.9 billion

  5. Cognitively active population: 8.9B × 0.75 = 6.675 billion

  6. Total IQ capacity (2045): 6.675B × 100 = 667.5 billion IQ points

  7. Percent loss by 2045: 20.3B ÷ 667.5B = ~3.04%

  8. Worst-case compounded scenario (high reinfection + high severity):

    • May approach 30% cumulative cognitive decline by 2045.

We incorporated a conservative reinfection rate: one infection every three years per person, a trend now well-supported by global re-infection surveillance. The model assumes that neurological symptoms become more likely and more damaging with each successive infection, which is also supported by widespread clinical findings. While first infections may pass with minimal long-term impact, second infections raise the likelihood of impairment, and third or subsequent infections are assumed to result in neurological symptoms in approximately 50% of cases (50% figure is an estimation). This is consistent with published data in 2023 by Frontiers in Immunology, which showed worsened Long COVID outcomes in repeat-infected individuals.

While any one case may appear clinically manageable, the global scale introduces a disturbing aggregate outcome. By 2045, the world may experience a cumulative loss of approximately 30% of its cognitive capacity — as measured by average IQ-weighted functionality across the working population. This does not mean that 30% of people become disabled, but rather that the distributed neurological burden is equivalent to losing 30% of the intellectual “processing power” of the human species.

Importantly, this model assumes no meaningful remediation — no perfected immunization model, no major advances in neuroprotective care or cell repair protocols, no demographic offsets, etc. In reality, these factors will likely moderate the curve. However, in the absence of serious international response, the trajectory remains plausible — and deeply concerning.

Acknowledgements / Model Nuance:

  • Assumption Accuracy: The entire model hinges on the accuracy of the initial baselines (infection rates, Long COVID rates, neurological involvement, IQ point loss per case, reinfection rates, and neurological risk per reinfection). Any significant deviation in these could drastically alter the outcome.

  • Simplification of Neurological Impact: Reducing complex neurological impairments to a single IQ point loss might be an oversimplification. The real-world impact could manifest in various cognitive, emotional, and functional deficits not fully captured by IQ scores.

  • Homogeneity of Population: The model assumes a relatively uniform impact across the "cognitively active population." In reality, certain demographics might be disproportionately affected; there is evidence that suggests some people are more immune than others.

  • Not a Dynamic Model: The model is a simple static snapshot at 2025 and 2045. A more dynamic model that incorporates changing infection rates, evolving viral strains, and potential interventions over time might provide a more nuanced picture.

  • Long Timeframe: Predicting trends and impacts over a 20-year period inherently involves uncertainty.

While the preceding analysis presents a sobering outlook on the potential long-term neurological consequences of SARS-CoV-2 infection, it is important to recognize the provisional nature of such models. These projections, based on data available as of early 2025, are shaped by an evolving scientific understanding of viral persistence and immune response dynamics.

Possible Solution:

One of the most promising developments challenging this trajectory is the emergence of T-cell–based vaccine strategies. Unlike conventional antibody-centric vaccines, which primarily target early infection and symptom mitigation, T-cell vaccines are designed to generate durable immune responses capable of identifying and eradicating intracellular viral reservoirs. These reservoirs—hidden in tissues and inaccessible to neutralizing antibodies—are increasingly implicated in the pathophysiology of Long COVID, particularly in sustaining chronic inflammation and neuroinflammatory symptoms. This mechanism, if validated, may offer a therapeutic avenue for individuals experiencing persistent symptoms associated with post-viral syndromes; such vaccine technology must be made available regardless of possible patent rights.

References:

Tyler Fischella
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