Serological SARS‐CoV‐2 antibody response, potential predictive markers and safety of BNT162b2 mRNA COVID‐19 vaccine in haematological and oncological patients

Benda, Magdalena; Mutschlechner, Beatrix; Ulmer, Hanno; Grabher, Claudia; Severgnini, Luciano; Volgger, Andreas; Reimann, Patrick; Lang, Theresia; Atzl, Michele; Huynh, Minh; Gasser, Klaus; Petrausch, Ulf; Fraunberger, Peter; Hartmann, Bernd; Winder, Thomas

Haemato‐oncological patients are at risk in case of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) infection. Currently, vaccination is the best‐evaluated preventive strategy. In the present study, we aimed to assess serological response, predictive markers, and safety of BNT162b2 in haemato‐oncological patients. A total of 259 haemato‐oncological patients were vaccinated with two 30 µg doses of BNT162b2 administered 21 days apart. Serological response was assessed by ELECSYS(®) Anti‐SARS‐CoV‐2‐S immunoassay before vaccination, and at 3 and 7 weeks after the first dose (T1, T2). Safety assessment was performed. At T2 spike protein receptor binding domain (S/RBD) antibodies were detected in 71·4% of haematological and in 94·5% of oncological patients (P < 0·001). Haematological patients receiving systemic treatment had a 14·2‐fold increased risk of non‐responding (95% confidence interval 3·2–63·3, P = 0·001). Subgroups of patients with lymphoma or chronic lymphocytic leukaemia were at highest risk of serological non‐response. Low immunoglobulin G (IgG) level, lymphocyte‐ and natural killer (NK)‐cell counts were significantly associated with poor serological response (P < 0·05). Vaccination was well tolerated with only 2·7% of patients reporting severe side‐effects. Patients with side‐effects developed a higher S/RBD‐antibody titre compared to patients without side‐effects (P = 0·038). Haematological patients under treatment were at highest risk of serological non‐response. Low lymphocytes, NK cells and IgG levels were found to be associated with serological non‐response. Serological response in oncological patients was encouraging. The use of BNT162b2 is safe in haemato‐oncological patients.