Determinants of SARS-COV-2 vaccine response in CAR-T recipients

Muhammad Bilal Abid, MD, MRCP, Medical College of Wisconsin, Milwaukee, WI, elaborates on SARS-CoV-2 vaccine and chimeric antigen receptor T-cell (CAR-T)-related factors impacting vaccine response in CAR-T recipients. Increasing evidence has shown that this subset of immunocompromised patients have a considerably diminished immune response to SARS-CoV-2 vaccines. This response can be influenced by several vaccine-related factors including the type of vaccine, spike mRNA content, interval between CAR-T infusion and first vaccine dose, interval between the two vaccine doses, interval between the second dose, response assessment, and platform used to assess antibody response. Dr Abid explains that CAR-T recipients usually have a better response to the Moderna vaccine, because it has a higher mRNA content and allows a longer interval between the two doses. It is also important to wait for a minimum of six months after CAR-T therapy before administering the first vaccine dose. Factors driving vaccine response related to the CAR-T construct include IgG levels at time of vaccination, CAR-T target antigen, lymphopenia at time of vaccination, status of disease before vaccination, treatment with immunosuppressive agents and immunomodulators, and prior allogeneic hematopoietic stem cell transplant (alloHSCT) before CAR-T therapy. This interview was recorded virtually.