The seasonal influenza A vaccine is recommended for patients with myeloproliferative neoplasms (MPNs). We hypothesised that immune deregulation associated with MPNs may affect the immune response gained following vaccinations when compared to healthy controls.
Using deep immunophenotyping with high‐dimensional single‐cell analysis and mass cytometry we could demonstrate an altered immune response in MPN patients following vaccination. We found that prior to vaccination, MPN patients had reduced numbers of naive CD4 T cells. Furthermore, at 3‐weeks and 3‐months post‐vaccination there was evidence of both delayed and impaired B‐ and T‐memory cells responses. Thus, although, the immune systems of MPN patients can ‘recognise’ the Influenza A vaccine, the response appears inferior compared to healthy controls.