Disseminated herpes zoster with varicella encephalitis and pneumonia following ChAdOx1 nCoV-19 (AZD1222) vaccine in an immunocompetent male-a case report.

A middle-aged gentleman, presented to our outpatient department with painful skin lesions suggestive of disseminated herpes zoster. Further examination revealed bilateral cerebellar signs. He had a history of receiving a third dose of AZD1222 vaccine fourteen days prior to the onset of skin lesions but had no other significant medical history. The patient was also evaluated for retroviral infection and other immunodeficient states, workup for which were negative. The patient was initially treated with intravenous acyclovir 7.5 mg/kg/q8H; however, the patient developed varicella encephalitis on treatment, which was followed by pneumonia and haemorrhagic cystitis. Subsequently, treatment was started with acyclovir 10 mg/kg/q8H for 14 days, followed by valacyclovir for eight days, following which there was near-complete resolution of symptoms with the persistence of minimal rigidity. Although there have been several reports of herpes zoster following SARS-CoV-2 vaccination, we found few reports of varicella zoster with systemic manifestations following ChAdOx1 nCoV-19 (AZD1222) vaccination. This case highlights the importance of considering varicella zoster reactivation in a patient presenting with encephalitis or pneumonia post SARS-CoV-2 vaccination.