T-Cell Response After SARS-CoV-2 Vaccination in Patients With Hematological Malignancy.

Patients with hematologic malignancies (HM) often mount poor humoral responses to SARS-CoV-2 vaccination due to their immunocompromised status. Protection against severe COVID-19 is strongly related to cellular immunity, yet vaccine-induced T-cell responses remain incompletely characterized. We conducted a systematic review of 87 studies assessing vaccine-induced T-cell response rates in HM. Across HM subtypes, 75%-87% of studies reported T-cell response rates of at least 50%. Active disease was associated with reduced T-cell responses. These findings indicate that SARS-CoV-2 vaccination can elicit cellular immunity in HM patients, including those receiving immunosuppressive therapy, supporting continued vaccination strategies even when humoral responses are suboptimal.