Ollila TA, Lu S, Masel R, et al. - COVID-19 vaccination may not induce adequate protection in patients with hematologic cancers, particularly in those undergoing B-cell–depleting immunotherapy, and hence, a potentially fatal infection may still develop in this population.

• In this retrospective study, researchers included adults with hematologic malignant disease who underwent vaccination with 1 of 3 COVID-19 vaccines authorized by the US Food and Drug Administration.

• Response to COVID-19 vaccines was examined in 160 patients with hematologic cancers [median age: 72 years; 86 (54%) males].

• Patients previously exposed to B-cell/plasma cell-depleting monoclonal antibodies, patients with active malignant disease vs those in remission after treatment or those under watchful waiting without any receipt of cancer therapy had significantly less frequent response to COVID-19 vaccine.

• Increased rates of seroconversion were observed in correlation with longer time from last chemotherapy administration to vaccination.

• Ongoing protective measures, including masks, social distancing, and screening, may benefit these patients.

• Vaccination for family members and caregivers should be prioritized to protect these patients.

• In cases with possible infection, testing should be taken regardless of vaccination status, and treatment is recommended with COVID-19–specific monoclonal antibody therapy.