Table 5.

Summary of significant clinical factors affecting seroconversion outcomes after COVID-19 vaccination in patients with cancer.

Positive predictors for seroconversion	Negative predictors for seroconversion
Favourable disease-related factors -Mutated immunoglobulin heavy chain (IGHV) genes [22] -β-2-microglobulin ≤3.5 mg/L [22] -Early disease stage [22]	Older age ->65 years [22,28] -≥68 years [32] -≥70 years [31]
Naïve or time lapsed from active treatment [18,22,34] -≥12 months from the last anti-CD20 therapy at the time of vaccination [22,30]	Haematological malignancies [16,27,33]
Higher serum immunoglobulin levels at the time of vaccination [17,21,34] -IgG levels ≥550 mg/dL [22] -IgM levels ≥40 mg/dL [22]	Cytotoxic chemotherapy [16,17,26,28] -Hydroxycarbamide [25]
Hormonal therapy [33]	Immunotherapy [26] - Monoclonal antibody therapy [16] o Anti-CD20 (rituximab) therapy [22,25,30,31,33] o Anti-CD38 (daratumumab) therapy [29,35] - Prior immunosuppressive therapy o CAR T-cell therapy [33] o HSCT [33] -Immunomodulatory drugs (IMIDs) [25]
	Targeted therapy -BCL2 inhibitors (venetoclax) [22,25,31,34] -BTK inhibitors [22,25,31] -JAK1/JAK2 inhibitors (ruxolitinib) [25] -BCMA-targeted therapy [35]
	Active or progressive disease status [18,34]
	Immunoparesis [18,32]
	Lymphopenia [35]
	Increasing lines of treatment [34,35]
	Heightened pre-vaccination lactate dehydrogenase (LDH) levels [34]

IgG, immunoglobulin G; CAR, chimeric antigen receptor-modified; HSCT, haematopoietic stem cell transplantation; BCL2, B-cell lymphoma 2; BTK, Bruton tyrosine kinase; JAK1/JAK2, Janus kinase 1/2; BCMA, B-cell maturation antigen.