LAUSR

A 50-year-old woman presented with left shoulder pain that developed 1 day after the intramuscular administration of a zoster vaccine (Picture 1). She had been experiencing this pain for the past six weeks. Magnetic resonance imaging (fat suppression T2-weighted imaging) revealed subacromial bursitis and tendinitis of the supraspinatus and biceps (Picture 1A-D). She was diagnosed with a shoulder injury related to vaccine administration (SIRVA). SIRVA has recently been reported as a side-effect after receiving the coronavirus disease-2019 vaccine (1). However, many medical professionals in Japan are unaware of SIRVA, since most vaccines are administered subcutaneously. To reduce the risk of SIRVA, vaccines administered intramuscularly should be injected at the deltoid area, between the anteroposterior axil-