CD38 and infection: In addition, contemporary International Myeloma Working Group (IMWG) guidance emphasizes infection-prevention measures, including vaccination (influenza, pneumococcal, COVID-19), antiviral prophylaxis for herpes zoster during proteasome inhibitor or anti-CD38 exposure, selective antibacterial prophylaxis in high-risk periods, and intravenous immunoglobulin for recurrent or severe infections with hypogammaglobulinemia, highlighting the clinical relevance of quantifying daratumumab-associated infection risk (19).