08/05/2025
😷 Still Masked, Still Right: A Data-Driven Case for Vigilance
This brief was prepared to support patients who continue to take precautions against SARS-CoV-2 and/or report symptoms that may be downplayed. The evidence summarized below reflects current peer-reviewed science on the effects of SARS-CoV-2 on the brain, immune system, cardiovascular system, and overall functioning—even after mild or asymptomatic infection.
1. SARS-CoV-2 is a vascular and neuroinvasive virus—not just a respiratory one.
▪ Neuroimaging data show measurable brain tissue loss, cognitive decline, and disrupted neural networks post- infection—even in non-hospitalized adults.1
▪ Cognitive deficits resembling IQ loss, attentional dysfunction, and memory decline are well-documented in both adults and children.2,3
▪ Viral particles have been found in the brain, vasculature, and bone marrow months after infection. 4,5,6
2. Damage occurs even after “mild” or asymptomatic infections.
▪ Studies confirm structural and functional brain changes after mild cases, particularly in areas responsible for memory, attention, and executive function.7,8
▪ Many individuals show signs of organ dysfunction (e.g., cardiovascular, renal) without overt symptoms—just as in hypertension or cancer before clinical presentation.9,10
3. SARS-CoV-2 impairs immune function—sometimes long-term.
▪ T-cell exhaustion, persistent inflammation, and immune dysregulation are well-documented months after infection.10-12
▪ Children also experience neutrophil dysfunction and inflammatory syndromes despite mild illness.13-15
4. Children are not spared their other organs.
▪ A major cohort study of nearly 300,000 infected children showed increased risk of myocarditis, arrhythmias, thromboembolism, and heart failure months after infection.16
▪ Kidney dysfunction and neuropsychiatric manifestations have been reported in pediatric populations.17,18
5. Functional impairment is often invisible but real.
▪ Individuals may struggle with cognition, fatigue, sensory overload, or post-exertional malaise even if routine labs appear “normal” yet they may perform poorly at mental tasks or while operating heavy machinery, including driving19,20.
6. Masking and other protections are rational—not pathological.
▪ A person choosing to wear a high-quality mask, even when not ‘fitted’ in a clinical setting is applying layered, evidence-based risk reduction.21
▪ Avoiding repeat infections is not fear—it is a science-informed strategy to protect brain, heart, immune, and societal health. These are just facts.
This summary reflects peer-reviewed research from top-tier journals and global experts. For references and further reading, see reverse side.
Fact Sheet Prepared by:
Sean P. Mullen, PhD
Associate Professor, Health and Kinesiology Director, Exercise, Technology, and Cognition Lab University of Illinois Urbana-Champaign
Last updated May 7, 2025
References
1. Wood GK, Sargent BF, Ahmad ZU, et al. Posthospitalization COVID-19 cognitive deficits at 1 year are global and associated with elevated brain injury markers and gray matter volume reduction. Nat Med. Published online 2024. doi:10.1038/s41591-024-03309-8.
2. Douaud G, Lee S, Alfaro-Almagro F, et al. SARS-CoV-2 is associated with changes in brain structure in UK Biobank. Nature. 2022;604(7907):697-707. doi:10.1038/s41586-022-04569-5
3. Hampshire A, Azor A, Atchison C, et al. Cognition and memory after COVID-19 in a large community sample. N Engl J Med. 2024;390(9):806-818. doi:10.1056/NEJMoa2311330..
4. Monje M, Iwasaki A. The neurobiology of long COVID. Neuron. 2022;110(22):3484-3496. doi:10.1016/j.neuron.2022.10.006.
5. Stein SR, Ramelli SC, Grazioli A, et al. SARS-CoV-2 infection and persistence in the human body and brain at autopsy. Nature. 2022;612(7941):758-763. doi:10.1038/s41586-022-05542-y.
6. Rong Z, Mai H, Ebert G, et al. Persistence of spike protein at the skull-meninges-brain axis may contribute to the neurological sequelae of COVID-19. Cell Host Microbe. Published online November 29, 2024. doi:10.1016/j.chom.2024.11.007.
7. Samanci B, Ay U, Gezegen H, et al. Persistent neurocognitive deficits in long COVID: Evidence of structural changes and network abnormalities following mild infection. Cortex. 2025;187:98–110. doi:10.1016/j.cortex.2025.04.004
8. Xu E, Xie Y, Al-Aly Z. Long-term neurologic outcomes of COVID-19. Nat Med. 2022;28(12):2406-2415. doi:10.1038/s41591-022-02001-z.
9. Ewing AG, Salamon S, Pretorius E, et al. Review of organ damage from COVID and Long COVID: a disease with a spectrum of pathology. Med Rev. 2024;5(1):66-75. doi:10.1515/mr-2024-0030
10. Kubisiak A, Dabrowska A, Botwina P, et al. Remodeling of intracellular architecture during SARS-CoV-2 infection of human endothelium. Sci Rep. 2024;14:29784. doi:10.1038/s41598-024-80351-z.
11. Phetsouphanh C, Darley DR, Wilson DB, et al. Immunological dysfunction persists for 8 months following initial mild- to-moderate SARS-CoV-2 infection. Nat Immunol. 2022;23(2):210-216. doi:10.1038/s41590-021-01113-x.
12. Pedroso RB, Torres L, Ventura LA, et al. Rapid progression of CD8 and CD4 T cells to cellular exhaustion and senescence during SARS-CoV-2 infection. J Leukoc Biol. 2024;116(6):1385-1397. doi:10.1093/jleuko/qiae180.
13. Chou J, Thomas PG, Randolph AG. Immunology of SARS-CoV-2 infection in children. Nat Immunol. 2022;23(2):177- 185. doi:10.1038/s41590-021-01123-9.
14. Bodansky A, Mettelman RC, Sabatino JJ Jr, et al; Overcoming COVID-19 Network Investigators. Molecular mimicry in multisystem inflammatory syndrome in children. Nature. 2024;632(8025):622-629. doi:10.1038/s41586-024-07722-4.
15. Kovács F, Posvai T, Zsáry E, et al. Long COVID syndrome in children: neutrophilic granulocyte dysfunction and its correlation with disease severity. Pediatr Res. Published online November 27, 2024. doi:10.1038/s41390-024-03731-1.
16. Zhang B, Thacker D, Zhou T, et al. Cardiovascular post-acute sequelae of SARS-CoV-2 in children and adolescents: cohort study using electronic health records. Nat Commun. 2025;16:3445. doi: 10.1038/s41467-025-56284-0
17. Li L, Zhou T, Lu Y, et al. Kidney function following COVID-19 in children and adolescents. JAMA Netw Open. 2025;8(4):e254129. doi:10.1001/jamanetworkopen.2025.4129
18. Ewing AG, Joffe D, Blitshteyn S, et al. Long COVID clinical evaluation, research, and impact on society: a global expert consensus. Ann Clin Microbiol Antimicrob. 2025;24(1):Article 793. doi:10.1186/s12941-025-00793-9
19. Erdik B, Homrich D. Driving under the cognitive influence of COVID-19: exploring the impact of acute SARS-CoV-2 infection on road safety. Neurology. 2024;103(7_Suppl_1):S46-S47. doi:10.1212/01.wnl.0001051276.37012.c2
20. Erdik B. Driving under viral impairment: Linking acute SARS-CoV-2 infections to elevated car crash risks. PLOS Glob Public Health. 2025;5(4):e0004420. doi:10.1371/journal.pgph.0004420
21. Greenhalgh T, MacIntyre CR, Baker MG, et al. Masks and respirators for prevention of respiratory infections: a state of the science review. Clin Microbiol Rev. 2024;37(2):e00124-23. doi:10.1128/cmr.00124-23
Further Reading & Public Resources
• The Hidden Damage to the Immune System
• Why I Still Wear an N95 – A Doctor’s Perspective | Stuck in the Middle with Masking – Playing the Long Game
Last updated May 7, 2025