Figure 5: Proposed mechanism of tumor hyperprogression following COVID-19 vaccination. (A) Conceptual model illustrating how inoculation with mRNA vaccine leads to immune reactions depending on its biodistribution. Strong immunostimulation can override immunosurveillance of latent cancer cells and trigger tumor hyperprogression. (B) Schematic representation of the major immune cell types influencing tumor growth and immune regulation following mRNA vaccine exposure. LNP-encapsulated modified mRNA (modRNA/mRNA) interacts with innate immune sensors altering cytokine signaling (TNF-α, IL-1β, IL-6) and immune-cell polarization leading to immunosuppression and reduced cytotoxic CD8⁺ T-cell activity. Expansion of myeloid suppressor populations, along with pro-tumor cytokine feedback loops, fosters accelerated tumor cell proliferation and immune evasion. The imbalance between anti-tumor (M1, CD8⁺, NK) and pro-tumor (M2, Treg, MDSC) networks favors tumor hyperprogression.