Abstract
Recent data suggest that protective immunity from COVID-19 vaccine may wane after a period, with booster doses becoming increasingly deployed in many countries. An 84-year-old woman presents with a 6-month history of left upper-limb swelling; the only history of note was an intramuscular Pfizer-BioNTech mRNA vaccine booster in the ipsilateral deltoid just 1 week before the onset of the swelling. Upper-extremity lymphoscintigraphy after the administration of 99m Tc-nanocolloid into the interstitial space of the hands showed left upper-limb lymphatic dysfunction.