Fig. 2.

Following injection of the vaccine, the produced proteins or inactivated viruses cross the BBB (as in the SARS-CoV-2) with molecular mimicry properties in the CNS, causing inflammation. Also, the production of S-protein by vector-based and mRNA vaccines causes activation of innate and adaptive immunity. In MS, immune cells identify vaccine-related antigens, invoking other immune cells, including T-cells, plasma cells, neutrophils, and macrophages. Afterward, they generate inflammatory cytokines that lead to cytokine storms, demyelination, and degeneration in neurons. In NMOSD, in addition to the cytokine storm and the invocation of immune cells, produced AQP4 IgG enters the CNS and binds to astrocytes’ feet. Complement mediators detect them, eventually causing astrocyte damage by inflammatory actions. Created with BioRender.com.