Vaccination for SARS-CoV-2 in Hematological Patients

Area of Science:

• Hematology
• Immunology
• Infectious Diseases

Background:

• Patients with hematological malignancies (HM) face heightened risks from SARS-CoV-2 infection.
• COVID-19 vaccines are effective in healthy individuals, but immunocompromised populations were excluded from initial trials.

Purpose of the Study:

• To review the effectiveness and safety of COVID-19 vaccines in HM patients.
• To assess vaccine immunogenicity and identify factors influencing response in this population.

Main Methods:

• Review of non-randomized studies on COVID-19 vaccine effectiveness and safety in HM patients.
• Analysis of humoral and T-cell responses to vaccination in various HM subtypes and treatment regimens.

Main Results:

• COVID-19 vaccines are generally safe in HM patients, with similar adverse events to the general population.
• Low immunogenicity observed in lymphoproliferative disorders (e.g., non-Hodgkin lymphoma, chronic lymphocytic leukemia) and with specific therapies (anti-CD20, BTK inhibitors, ruxolitinib, venetoclax).
• Higher response rates seen in multiple myeloma and hematopoietic stem-cell transplant recipients, but not CAR T-cell therapy patients. Chronic myeloid leukemia and myeloproliferative diseases show good response.

Conclusions:

• A third mRNA vaccine dose is recommended for all HM patients.
• Alternative vaccination and prevention strategies are crucial for HM patients with suboptimal immune responses.