Table 1.

Summary of recommendations for SARS-CoV-2 vaccination according to the disease.

Disease	Background	Recommendations
Stem-cell transplantation	mRNA vaccines safe in SCT Priority Immunocompromised patients or with lung involvement Inactivated vaccines are active and do not worsen cGVHD Better seroconversion after SARS-CoV-2 mRNA vaccines	High transmission index: vaccination 3 months after SCT Medium/low transmission index: delay vaccination 6 months after SCT Delay vaccination in Severe cGVHD (grades III / IV) 3–6 months after anti-CD20 therapy 3 months after ATG or alemtuzumab Not recommended in < 16 years old Vaccination prior SCT repeat vaccination after SCT ASCT: Recommended prior harvesting If already harvested vaccination 3 months after ASCT Advisable to monitor response to vaccination in patients under immunosuppressive agents or with lymphocytopenia
CAR-T recipients	No consistent data on the use of vaccines	Optional prior CAR-T if no bridging chemo in the next 6 weeks 6 months after CAR-T, earlier if high community transmission rates If previously vaccinated, re-vaccinate 6 months after CAR-T Advisable to monitor response to vaccination
AML	High mortality of COVID-19 Prolonged neutropenia hampers antibody production Complex logistics of vaccination during treatment	Vaccination should not interfere with AML treatment AML in supportive care vaccination recommended according to life expectation AML in active therapy vaccine should be administered depending on the situation of the patient: Between consolidation cycles During maintenance when not candidate for SCT As soon as possible at the end of treatment
ALL	Inferior mortality in children compared to adults High case fatality rate in adults In children low immunization against other pathogens during treatment Blinatumomab B-cell depletion	Vaccination recommended according to the situation of the patient: At the end of induction Between consolidation treatments Anytime during maintenance treatment Anti-CD20 mAbs delay 3–6 months after the end of treatment, unless there is a high community transmission rate Blinatumomab vaccination recommended (relapsed patients) Vaccination not contraindicated with TKIs or inotuzumab Advisable to monitor response to vaccination in patients treated with monoclonal antibodies
Multiple Myeloma & plasma-cell disorders	COVID-19 increases mortality in MM compared to normal population Poor response to influenza vaccines Better seroconversion after SARS-CoV-2 mRNA vaccines	Not recommended when WBC < 500/ μL Active disease recommended during MM treatment, between cycles MM under control hold treatment between 7 days prior and 7 days after immunization Advisable to monitor response to vaccination in patients treated with IMIDs, monoclonal antibodies or BTK inhibitors
MDS	High mortality rate in MDS with COVID-19	MDS not receiving treatment with disease modifying agents vaccination as soon as possible Hypomethylating agents vaccination 1–2 prior next cycle of treatment Delay vaccination 6 months after last doses of ATG
CLL	High mortality rate in CLL with COVID-19 Low immunization after seasonal influenza vaccine Low rate of seroconversion after SARS-CoV-2 vaccine	Vaccination of CLL at any stage of the disease is a priority Delay vaccination 3–6 months after the end of anti-CD20 mAbs, unless there is a high community transmission rate Advisable to monitor response to vaccination in patients treated with monoclonal antibodies or BTK inhibitors
Lymphomas	High mortality rate in patients with lymphoma and COVID-19[72–77] Low immunization to seasonal influenza vaccine in patients treated with anti-CD20 mAbs Some differences in response rate after SARS-CoV-2 vaccine among different subtypes of NHL	Vaccination is recommended irrespective of the disease status Delay onset of lymphoma treatment (if possible) 3–6 weeks after vaccination. If delay is not possible, administer vaccine at the end of lymphoma treatment If mAbs against B or T-lymphocytes are employed, delay vaccination 3–6 months, unless there is a high community transmission rate. Patients receiving rituximab maintenance could interrupt treatment and resume it two months after vaccination Advisable to monitor response to vaccination in patients treated with monoclonal antibodies or BTK inhibitors
MPN and CML	High mortality in patients with myelofibrosis and COVID-19, compared to ET or PV Increased risk of thrombosis and COVID-19 in ET and PV	MPN should be considered a priority group irrespective of disease status or given disease treatment
Mast cell disorders	Outcomes similar to general population COVID-19 does not impact mast cell activation Unknown information on safety	Patients with mast cell disorders can receive vaccines. Contraindications are: Allergic reaction to the first dose (avoid the second dose) History of allergy to components of the vaccine, particularly PEG or tromethamine Vaccines should be administered in an environment expert in managing anaphylactic reactions
Aplastic Anemia (AA) and PNH	No data available so far	It is unlikely to observe an adequate immune response 6 months after receiving immunosuppressive treatment for AA (cyclosporine + ATG). After that period, it is possible to observe an immune response, even under cyclosporine maintenance No contraindications for SARS-COV-2 in PNH
Anticoagulants and hemorrhagic diathesis	Vaccines not contraindicated in patients with coagulation disorders Intramuscular route is adequate in well-controlled anticoagulated patients	INR should be in the target therapeutic range Patients receiving direct anticoagulants or low molecular weight heparin should avoid administration of vaccine during maximum peak plasma concentrations Platelet counts 25–50,000/µL compression of the puncture site Platelet counts < 25,000 / µL evaluate platelet transfusion Hemophilia no contraindication for intramuscular route All patients vaccine administered using a fine needle < 23G followed by compression for at least 3 minutes Prior history of heparin-induced thrombocytopenia (HIT): adenoviral-vector vaccines should be avoided, and mRNA-based vaccines used instead