• This prospective observational study involved the humoral immunogenicity of the seasonal inactivated influenza vaccine (IIV) in the context of CD19-, CD20-, and BCMA-targeted CAR-T-cell therapy. The participants were vaccinated either before or after CAR-T-cell therapy, and responses were compared with those of controls.
• The investigators found that the influenza vaccine was immunogenic both before and after CAR-T cell therapy. This finding was evident regardless of hypogammaglobulinemia and B-cell aplasia. Consequently, this vaccination can be given either before CAR-T cell therapy or with remission, per the authors.
• Strengths of this study included its novel design and prospective nature, as well as its use of gold-standard assays in a diverse sample of CAR-T-cell therapy recipients, as well as controls.
• According to the authors, “Data support consideration for administration of non-live vaccines before CAR-T-cell therapy for influenza, and by extrapolation, to other relevant pathogens in this clinical context (e.g., SARS-CoV-2 and pneumococcus). Additionally, vaccinations should be offered to patients in remission after CAR-T-cell therapy.”
• Limitations of this study included its small sample size. Furthermore, the provision of IIV was based on clinician acumen. Another limitation was the variation of vaccine types and timing of the sample collection secondary to clinical follow-up.
• “It is possible that undocumented influenza infection in between blood draws confounded measurements, but this is unlikely,” the authors conceded. “None of the vaccinations occurred within the first year after CAR-T-cell therapy, and additional data are needed to determine immunogenicity in these earlier time periods.”
This article is a preprint Preprints have not been peer reviewed. Learn more about preprints in the NIH Preprint Pilot. Recipients of chimeric antigen receptor-modified T (CAR-T) cell therapies for B-cell malignancies are immunocompromised and at risk for serious infections. Vaccine immunogenicity is unknown in this population.