Dr. Abid on the Efficacy of a Third COVID-19 Vaccine Dose After Hematopoietic Cell

Muhammad Bilal Abid, MD, MRCP, assistant professor of medicine, Divisions of Hematology/Oncology and Infectious Diseases, Medical College of Wisconsin, discusses the efficacy of a third COVID-19 vaccine dose after hematopoietic cell transplantation in patients with hematologic malignances.

Seventy-five patients were put together to study the efficacy of a third COVID-19 vaccine dosage after receiving hematopoietic cell transplantation, CAR T-cell therapy, or bispecific T-cell engagers (BiTEs), Abid says. This population included 30 autologous recipients, 26 allogeneic recipients, 10 CAR T recipients, 9 BiTEs recipients, Abid explains. Moreover, all 75 of the patients had not seroconverted to any degree after receiving two doses of the initial primary vaccination and 59% developed protective antibodies after the third dose, Abid says.

When stratified by subgroups, the seroconversion rates were 63% among autologous transplantation recipients, 58% among allogeneic transplantation recipients, and 40% among CAR T-cell recipients, and 67% among BiTE recipients, Abid explains. While there was no significant differences in seroconversion rates based on the state of contemporary relevant clinical variables, corticosteroid usage stood out in terms of conversion rates, Abid emphasizes.

Moreover, there was a significant difference between the titers among those patients who were receiving a dose of corticosteroids at the time of the third vaccination dose vs those who were not, Abid continues. On a subgroup analysis, a significant difference was noted between seroconversion rates among patients with multiple myeloma and lymphoma in autologous transplant subgroups, as seroconversion patients with myeloma converted better than patients with lymphoma, Abid concludes.