The current report represents a case of a 77-year-old man with Parkinson’s disease who died three weeks after receiving his third COVID-19 vaccination in January 2022. The patient was first vaccinated in May 2021 with the ChAdOx1 nCov- 19 vector vaccine, followed by two more doses with the BNT162b2 mRNA vaccine in July and December 2021. The family of the deceased requested an autopsy due to the ambivalent clinical features noted before death. The underlying illness (Parkinson’s disease) was confirmed by autopsy. However, no sign of a florid COVID-19 was discovered. Meanwhile, the immunohistochemical staining of the brain and heart revealed previously undiagnosed conditions. The brain, in distinctive, revealed multifocal necrotizing encephalitis with massive inflammatory lymphocyte infiltrates. In addition, the heart showed signs of serious myocarditis. Finally, immunohistochemical staining revealed that the SARS-CoV-2 spike protein was evident in the tissues investigated. Based on these immunohistochemical findings, it appears that the inflammatory changes in the patient's brain tissues are most likely the result of immunological processes. Concurrently, the absence of SARS-CoV-2 nucleocapsid-protein was evidenced, indicating that the detected spike-protein is unrelated to a SARS-CoV-2 infection. If such an infection was the cause of the spike protein, the SARS-CoV-2 nucleocapsid protein would also be detectable. As a consequence, the confirmed presence of the spike protein had to be attributed to the previous vaccination with the BNT162b2 mRNA vaccine that the deceased patient had received.