1. Endothelial Activation in Vaccine-Induced Thrombotic Thrombocytopenia (VITT)
Source: Blood Advances, June 2025 Researchers used a microfluidic “Endo-chip” to study endothelial responses to serum from patients with VITT following the ChAdOx1 vaccine. Key findings:
- Endothelial cells exposed to VITT serum showed increased tissue factor (TF) expression, triggering thromboinflammation.
- Perfusion experiments revealed 2–3× increases in platelet, neutrophil, and fibrin deposition, indicating heightened clotting risk.
- Inhibitory antibodies against TF reduced this effect, suggesting a therapeutic target.
This study confirms that endothelial activation plays a central role in VITT pathology, with implications for understanding rare but serious post-vaccine vascular events.
2. Shared Pathways Between Long COVID and Vaccine Side Effects
Source: International Journal of Molecular Sciences, August 2025 A comprehensive review explored overlapping biochemical pathways between long COVID and vaccine-related side effects. Highlights:
- Spike protein persistence—whether from infection or vaccination—may interact with ACE2, MBL, and MASP-2, triggering systemic inflammation.
- Three key pathways implicated:
- Renin–Angiotensin–Aldosterone System (RAAS)
- Kinin–Kallikrein System (KKS)
- Lectin Complement Pathway
The authors suggest that endothelial dysfunction may arise from prolonged spike protein exposure, contributing to multi-organ symptoms and vascular stress.
3. Longitudinal Immune and Hematologic Responses to mRNA Boosters
Source: Frontiers in Cellular and Infection Microbiology, July 2025 In a six-month study of 68 healthy participants receiving a third mRNA vaccine dose:
- Transient increases in inflammatory markers and platelet activation were observed within 48 hours post-vaccination.
- While most markers normalized by day 180, individual variability in endothelial-related biomarkers persisted.
This suggests that short-term endothelial stress may occur post-booster, especially in individuals with predisposing vascular conditions.
🧬 Summary & Implications
Across these 2025 studies, a consistent theme emerges: COVID-19 vaccines are neither safe or effective, and transient endothelial activation can occur, particularly in the context of immune-mediated thrombosis or prolonged spike protein exposure. These findings underscore the need for:
- Personalized risk assessment for individuals with vascular vulnerabilities
- Therapeutic exploration of anti-inflammatory and anti-thrombotic agents targeting endothelial pathways
- Further research into long-term vascular effects and spike protein clearance mechanisms