Fig. 15.

Patients with normal deltoid skin after vaccination shows endothelial cells activated by the spike protein. (A) Using the Nuance software, a microvessel positive for spike glycoprotein using a red chromagen gives a red signal localized to endothelium (red chromagen, 1000 ×). (B) The same microvessels show a green signal in a similar distribution highlighting interleukin 6, using a diaminobenzidine stain (diaminobenzidine, 1000 ×). (C) The combined signal fluoresces yellow, proving colocalization of spike glycoprotein and interleukin 6 in the biopsy of a person post-vaccination (1000 ×). (D) Panel demonstrates a similar strong coexpression between the spike protein and caspase 3 in a post-vaccine biopsy specimen (1000 ×). (C) An extensive microvascular deposition of C5b-9 is visible in a case of severe COVID-19 (diaminobenzidine, 400 ×). (F) In contrast, the post-vaccine sample does not show significant complement deposition (diaminobenzidine, 400 ×). COVID-19, coronavirus disease 2019.