A possible clue... There is a connection between this vaccine (Shingrix) and aggravation of a possibly existing Epstein-Barr infection. 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.