LAUSR

COVID‐19 is a potential life‐threatening viral disease caused by SARS‐CoV‐2 and was declared a pandemic by the WHO in March 2020. mRNA‐based SARS‐CoV‐2 vaccines are routinely recommended in immune‐compromised patients, including patients with AA, as these patients are at increased risk of contracting COVID‐19 and developing a more severe course of disease. Between March 2021 and November 2021 relapse of AA occurred in four (age [median]: 53 years, range 30–84 years) out of 135 patients currently registered at our department and two de novo cases of AA in temporal context to vaccination against SARS‐CoV‐2, were documented. Median time after first COVID‐19 vaccination and relapse of AA was 77 days. All relapsed patients were vaccinated with the mRNA‐based vaccine Comirnaty®. Relapse in two out of the four patients was refractory to CsA/eltrombopag, favoring IST with hATG/CsA or BMT, respectively. Our observations should prompt clinicians to take vaccine‐induced relapse of AA or de novo AA after SARS‐CoV‐2 vaccination into account. Furthermore, careful clinical monitoring and vigilance for signs or symptoms that may indicate relapse of AA (e.g., bleeding complications) are indicated.