CD4 and Dravet syndrome: Nonetheless, the lower antibody titers in adults with DS after primary vaccination – which might be linked to the lower percentage of SARS-CoV-2 specific CD4+ T cells after mRNA vaccination – as observed previously15–17 should not be overlooked, nor that DS remains a risk factor for severe disease even after vaccination.10 Booster vaccination increased T-cell function in DS to levels similar to those observed in HC, indicating that implementing booster vaccinations in vaccine schedules for individuals with DS may be an effective strategy to enhance protection in this vulnerable population.