Immunogenicity and risks associated with impaired immune responses following SARS-CoV-2 vaccination and booster in hematologic malignancy patients: an updated meta-analysis

Category	Detail
Condition	Hematologic malignancies (e.g., AML, MDS) with SARS-CoV-2 infection risk
Key Mechanisms	Impaired humoral and cellular immune responses post SARS-CoV-2 vaccination; variable seroconversion rates influenced by malignancy subtype and treatment
Target Population	Adult patients with hematologic malignancies without prior SARS-CoV-2 infection
Care Setting	Clinical oncology and hematology outpatient and inpatient settings managing COVID-19 vaccination

Approximately two-thirds of hematologic malignancy patients achieve seroconversion after complete SARS-CoV-2 vaccination, compared to ~90% in solid cancer patients.
Cell-mediated immune responses may provide protection in patients with impaired humoral immunity, but are rarely evaluated.
Booster doses are offered to seronegative patients post-primary vaccination, but their impact on seroconversion in hematologic malignancies remains largely undefined.

Assess seroconversion using anti-spike SARS-CoV-2 IgG antibody levels post-vaccination.
Consider evaluation of cellular immune responses where feasible to assess protection in seronegative patients.

Administer complete primary vaccination series (2 doses mRNA or adenoviral vector vaccines, or single dose Ad26.COV2.S) to hematologic malignancy patients.
Offer booster doses to patients with negative seroconversion following primary vaccination.

Monitor seroconversion rates post-vaccination to identify patients with poor humoral response.
Evaluate impact of different hematologic malignancy subtypes and treatment modalities on vaccine immunogenicity.

Higher mortality risk from COVID-19 in hematologic malignancy patients compared to solid cancer patients.
Potential for poor vaccine-induced immune response due to disease and treatment-related immunosuppression.

Adults with hematologic malignancies undergoing SARS-CoV-2 vaccination

Seroconversion rates vary by malignancy subtype and treatment; booster doses may improve immune response but data are limited.

Use standardized assays to measure anti-spike antibody levels for consistent seroconversion assessment.
Incorporate assessment of cellular immunity when possible to better understand vaccine protection in seronegative patients.
Tailor vaccination strategies considering hematologic malignancy subtype and ongoing treatments to optimize immune response.
Encourage booster vaccination in patients with inadequate initial seroconversion to enhance protection.

Clinical Scorecard: Evaluation of Immune Response and Associated Risks Following SARS-CoV-2 Vaccination and Boosters in Patients with Hematologic Malignancies: A Comprehensive Meta-Analysis