Impact of Bacille Calmette-Guérin vaccination on the therapeutic schedule of infantile epileptic spasms syndrome: A 25-year Japanese single-center survey

Adrenocorticotropic hormone (ACTH) therapy is effective for infantile epileptic spasms syndrome (IESS) but can induce immunosuppression. In Japan, Bacille Calmette-Guérin (BCG) vaccination, modified in 2013 to reduce osteitis/osteomyelitis risk, coincides with the peak onset age of IESS. This raises concerns about infection risks when administering ACTH therapy post-vaccination. To evaluate the impact of BCG vaccination timing on treatment decisions, we retrospectively reviewed the medical records of 86 IESS patients at our hospital (1996–2020). Infants who received ACTH therapy within eight weeks of BCG vaccination experienced no serious adverse events. Four patients deferred or opted out of ACTH therapy, with seizure remission taking 2–15 weeks. The overlap between IESS onset and BCG vaccination period presents clinical challenges in determining the appropriate timing for ACTH therapy. Further epidemiological and immunological research is needed to clarify the relationship between ACTH therapy and BCG-associated adverse events and to optimize treatment strategies and vaccination schedules.