Covid-19 Vaccine Response in Immunocompromised Haematology Patients

"Participants will have blood tests at baseline (nearest 30 day incremental time point after 2nd dose of Covid-19 vaccine, +/- 7 days):~* T, B \& NK cells~* Full Blood Count and differential~* Serum Immunoglobulins~* Antibodies against VZV, CMV, Rubella~* Quantiferon assay (T-Cell response)~* Covid antibody assay (LIAISON® SARS-CoV-2 S1/S2 IgG quantitative assay)~Participants will have blood tests during follow up (after second dose of Covid-19 vaccine) with a window of +/- 7 days:~* Blood test 2 - performed at the next 30 day time point (Covid antibody assay)~* Blood test 3 - performed at the next 30 day time point (Covid antibody assay and quantiferon\* if final blood test)~* Blood test 4 (optional) - performed at the next 30 day time point (Covid antibody assay)~* Blood test 5 (optional) - performed at the next 30 day time point (Covid antibody assay and quantiferon\* if final blood test)~ * Quantiferon assay will be only be performed where possible."