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. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Kings Together Rapid COVID-19 Call awards to MHM, KJD, A Huo Family Foundation Award to MHM, KJD, Chronic Disease Research Foundation award CDRF-22/2020 to KJD, MHM, part of the EDCTP2 programme supported by the European Union (RIA2020EF-3008 COVAB) to KJD, MHM, MRC Genotype-to-Phenotype UK National Virology Consortium (MR/W005611/1) to MHM, KJD, Wellcome Trust Investigator Award 106223/Z/14/Z to MHM, CG was supported by the MRC-KCL Doctoral Training Partnership in Biomedical Sciences (MR/N013700/1), Fondation Dormeur, Vaduz for funding equipment to KJD, MPN Voice Grant to CH and DM ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The research project received ethical approval from the West Midlands - Edgbaston Research Ethics Committee (REC reference 20/WM/0187). Integrated Research Application ID 285396. All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes The datasets generated during and analysed during the current study are available from the corresponding author on reasonable request.