莫德納疫苗 (Moderna COVID-19 vaccine, mRNA-1273) 為mRNA 型新型冠狀肺炎疫苗，於其第三期臨床試驗COVE (coronavirus efficacy) 之期中分析 (interim analysis) 展現高達94.1% 新冠肺炎預防效力，並於2020 年12 月獲U.S. Food and Drug Administration 緊急授權。於該臨床試驗中，皮膚不良反應除了常見的立即性注射部位反應外，亦有觀察到特殊的遲發性局部反應，此類反應因於試驗中僅佔0.8% 而未受到重視。隨疫苗於真實世界施打率增加，國外重點刊物陸續報導此類特殊情況，並特稱為「新冠手臂 (COVID arm)」。而臺灣第一批莫德納疫苗於2021 年6 月開始施打，隨施打率增加，預計新冠手臂案例會陸續增多。為提升疫苗不良反應之認知度，避免「疫苗猶豫 (vaccine hesitancy)」，提供本案例序列報告與文獻討論，提供醫療人員照護參考。本研究序列報告探討3 位案例於疫苗注射後中位數天數第8天，開始出現新冠手臂症狀，包括大型紅斑、大面積紅腫發癢，乃至如拳頭般尺寸之紅腫浮起硬塊，症狀先由惡化轉為自行改善，歷時10 天以上緩解。經文獻顯示，該類症狀應屬疫苗導致之新冠手臂現象，好發於女性個案，推測機轉與T 細胞媒介型反應有關，潛伏期約長達1 週。雖病灶外觀與不適感可能引起民眾疑慮，或誤診為蜂窩性組織炎，但多數案例症狀屬輕微且為自限性，並非施打第二劑疫苗之禁忌症，建議仍繼續完成疫苗注射，以確保完整疫苗保護力。

 

The Moderna COVID-19 vaccine (Moderna COVID-19 vaccine, mRNA-1273) demonstrated 94.1% efficacy in preventing COVID-19 illness at the interim analysis of the ongoing phase 3 COVE (coronavirus efficacy) trial. Its preliminary results contributed to U.S. Food and Drug Administration emergency use authorization in December 2020. Apart from common immediate injection site reactions, delayed skin reactions were also observed but were accounted for only 0.8% in the safety assessment. As vaccination rise in the real world, leading medical journals published several cases with vaccine-associated delayed localized cutaneous reactions, dubbed “COVID arm”. The first batch of Moderna vaccines was available in June 2021. With an increase in the rate of vaccination, cases with COVID arm are expected to grow. To recognize vaccine associated-delayed reactions and avoid “vaccine hesitation”, herein we reported on a series of 3 cases with COVID arm to the Moderna vaccine with a median onset on day 8 (range, 7 to 10) after the first dose. These reactions included large erythema, extensive itching redness over the upper arm, and fist-sized induration. All of the symptoms resolved spontaneously with a duration of up to 10 days more. According to literature reviews, the pathophysiology was suggested to be T-cell-mediated based on the histopathologic finding. This reaction was more common in females and had a specific trait of one-week delay after vaccination. Although the lesion might be large and discomfort enough to cause concerns or be misdiagnosed as cellulitis, these symptoms are usually self-limited. Therefore, reactions with the COVID arm are not affirmed as contraindications to receiving the second dose of vaccine. Completion of vaccination is encouraged to ensure vaccine efficacy. 

 

 

Summited for publication: 2021.7.2; Accepted for publication: 2021.8.31