Einarsdottir S, Martner A, Nicklasson M, Wiktorin HG, Arabpour M, Törnell A, Vaht K, Waldenström J, Ringlander J, Bergström T, Brune M, Hellstrand K, Ljungman P, Lagging M. Reduced immunogenicity of a third COVID-19 vaccination among recipients of allogeneic hematopoietic stem cell transplantation. Haematologica 2022;107(6):1479-1482; https://doi.org/10.3324/haematol.2021.280494.