Sporadic Kaposi Sarcoma Following a COVID-19 Vaccine: Mere Coincidence or Something More?

"Abstract: In this case report, we present a distinctive occurrence of classic Kaposi sarcoma (KS) in an individual of Latin origin, emerging seven days following the administration of the third dose of the ChAdOx1 nCoV-19 (AstraZeneca) vaccine. The progression of KS continued over two months, culminating in the development of a tumor. Given the absence of prior reports on KS development post-COVID-19 vaccination, the primary aim of this report is to explore the potential relationship between the ChAdOx1 nCoV-19 vaccine, reactivation of Kaposi sarcoma-associated herpes virus, and the subsequent onset of KS ...

Discussion: We conducted a thorough search on PubMed and Google Scholar using the keywords 'Kaposi sarcoma' or 'Kaposi tumor' in combination with 'vaccine' and 'COVID-19.' Despite our efforts, we found no articles linking KS to any COVID-19 vaccination. While the strong epidemiological correlation makes it less likely for other factors to be the cause, the absence of a background compelled us to speculate on potential mechanistic theories. KSHV [Kaposi sarcoma-associated herpes virus] is an absolute requirement of oncogenesis and is a direct carcinogen, so when we are looking into the relationship between the AstraZeneca vaccine and Kaposi sarcoma, we may focus on the reactivation of KSHV.

Studies have shown that spike proteins of SARS-CoV-2 can reactivate the lytic phase of KSHV. The ChAdOx1 nCoV-19 vaccine contains DNA eDNA-encoding proteins. If these spike proteins encounter HHV8-infected cells, it could potentially trigger the reactivation of the virus, leading to the lytic phase. The reactivation of KSHV may also be influenced more by the immune inflammation stimulated by the adenovirus vector rather than the spike proteins themselves."