Single dose of BNT162b2 mRNA vaccine against SARS-CoV-2 induces high frequency of neutralising antibody and polyfunctional T-cell responses in patients with myeloproliferative neoplasms

Encouraging results have been observed from initial studies evaluating vaccines targeting the novel beta coronavirus which causes severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, concerns have been raised around the efficacy of these vaccines in immunosuppressed populations, including patients with haematological malignancy. Myeloproliferative neoplasms (MPN), in particular myelofibrosis (MF), are associated with heterogenous immune defects which are influenced by patient age, disease subtype and the use of cytoreductive therapies. Patients with a WHO defined diagnosis of an MPN presenting to our clinic were recruited following first injection of 30μg BNT162b2. A positive anti-S IgG ELISA was seen in 76.1% (16) of patients following vaccination with positive neutralising antibodies detected in 85.7% (18) of patients. A memory T cell response was observed in 80% (16) of patients, with a CD4+ T cell response in 75% (15) and a CD8+ T cell response in 35% (7). These results, for the first time, provide some reassurance regarding the initial immune response to the BNT162b2 vaccine amongst patients with MPN, with response rates similar to that observed in the general population.