Improving SARS-CoV-2 vaccine responses in CAR-T recipients

Muhammad Bilal Abid, MD, MRCP, Medical College of Wisconsin, Milwaukee, WI, comments on the value of booster vaccines and novel vaccine strategies in chimeric antigen receptor T-cell (CAR-T) recipients. Multiple lines of evidence have shown that CAR-T recipients have suboptimal responses to the SARS-CoV-2 vaccines, with a humoral response rate (RR) ranging between 14-28%. Nevertheless, there is considerable heterogeneity amongst these studies and it is thus important to conduct further research on this topic. Dr Abid argues that a booster vaccine is not likely to have a significant effect on CAR-T recipients, since they have already have a low RR to the first two doses. Hence, these patients should continue with mitigation strategies. Ongoing studies are investigating novel strategies to improve responses to SARS-CoV-2 vaccines in CAR-T recipients. For instance, a large prospective study is currently evaluating heterologous prime-boost in CAR-T recipients. In addition, exploring different intervals both between vaccine doses and between CAR-T infusion and first vaccine dose, as well as the role of prophylactic monoclonal antibodies, are methods that should be investigated in the future. This interview was recorded virtually.