Unexpected hypereosinophilia after Sinopharm vaccination: a case report

COVID-19 vaccines have been pivotal in the management of the recent pandemic. However, despite their safety and efficacy, apprehension regarding possible adverse effects has always been raised. Most of the vaccine-related side effects are mild. However, serious complications like anaphylaxis and thromboembolic events have also been reported. Various hematological disorders, including hypereosinophilia, have been reported following COVID-19 vaccination, the exact mechanisms of which remain unclear.

We report a 66-year-old male who developed hypereosinophilia (absolute eosinophil count: 4063 cells/µL) and lymphadenopathy two months after receiving the third dose of the BBIBP-CorV (Sinopharm) COVID-19 vaccine. Extensive investigations failed to identify an alternative cause for these findings.

This case report underscores the potential for unexpected hematological adverse events following COVID-19 vaccination, even with inactivated vaccines. While a definitive causal relationship cannot be established, the temporal association between vaccination and symptom onset warrants further investigation. This case emphasizes the importance of continued surveillance for rare adverse events and additional research to elucidate the potential mechanisms underlying vaccine-associated eosinophilia.