Sex: M
Vaccine: RVX
Symptoms: Scan with contrast abnormal, Varicella virus test negative, Viral test negative, White blood cell count increased
Clinical narrative: Acute disseminated encephalomyelitis; varicella zoster virus meningoencephalitis; abnormality in the superior cerebellar peduncles/Possible midbrain abnormality/corticospinal tracts; Mutism; This serious case was reported by a consumer via regulatory authority and described the occurrence of acute disseminated encephalomyelitis in a 64-year-old male patient who received RSVPreF3 adjuvanted (RSV vaccine) for prophylaxis.   Concurrent medical conditions included hypertension, gout, chronic kidney disease and herpes zoster. Concomitant products included valaciclovir (Valacyclovir), paracetamol (Acetaminophen), allopurinol, amlodipine and metoprolol.   On 11-NOV-2023, the patient received RSV vaccine. In NOV-2023, 4 days after receiving RSV vaccine, the patient experienced acute disseminated encephalomyelitis (Verbatim: Acute disseminated encephalomyelitis) (serious criteria hospitalization and GSK medically significant), varicella zoster encephalitis (Verbatim: varicella zoster virus meningoencephalitis) (serious criteria hospitalization and GSK medically significant), nervous system disorder (Verbatim: abnormality in the superior cerebellar peduncles/Possible midbrain abnormality/corticospinal tracts) and mutism (Verbatim: Mutism). The patient was treated with aciclovir (Acyclovir). The outcome of the acute disseminated encephalomyelitis and varicella zoster encephalitis were resolving and the outcome of the nervous system disorder and mutism were not reported.   It was unknown if the reporter considered the acute disseminated encephalomyelitis, varicella zoster encephalitis, nervous system disorder and mutism to be related to RSV vaccine.     It was unknown if the company considered the acute disseminated encephalomyelitis, varicella zoster encephalitis, nervous system disorder and mutism to be related to RSV vaccine.   Additional Information: GSK Receipt Date: 12-MAR-2024 The medications at time of vaccination included Valacyclovir, Acetaminophen, Allopurinol, Amlodipine and Metoprolol. The medical history included hypertension, gout, chronic kidney disease with no allergies known. This report described the occurrence of ADEM (Acute disseminated encephalomyelitis) in a patient who received an RSV vaccine (batch not stated) and experienced ADEM 4 days later.  It was reported that he developed a single dermatomal zoster lesion and was prescribed Valacyclovir by his PCP (primary care physician).  He went to the pharmacy to obtain the medication.  At the pharmacy he also received an RSV vaccine.  The report stated that he/she was not sure whether it was Abrysvo or Arexvy as that information was not available to him/her at this time.  In the early AM 15th November 2023, they woke up confused.  He was admitted to the hospital later that day with concerned of VZV (varicella zoster virus) meningoencephalitis and was treated with intravenous (IV) Acyclovir.  Based on imaging studies and labs he did not have central nervous system involvement and was then diagnosed with ADEM and treated with IV steroids with notable improvement. The PCR (polymerase chain reaction) testing for VZV and other tested viruses were negative.  The brain MRI (magnetic resonance imaging) without contrast was performed on 15th January 2024 and twice with contrast on 16th January 2024.  A neurology note stated that review of his brain MRIs showed that these might explain mutism and possible involvement of the corticospinal tracts.