A possible clue... There is a connection between this vaccine (Shingrix) and aggravation of an Epstein-Barr related Guillain-Barre syndrome. EBV is the cause of MONONUCLEOSIS. My monocyte levels were though the roof, yet the ER doc, my primary care doc, and a Rheumatologist at a well respected hospital failed to address this, as well as other extreme reactions. As a matter of fact , I have yet to get a referral to any docs with immunological smarts. I filed an adverse event report more than 6 months ago and still have ill effects from the vaccine.