Typhoid vaccine trial confirms sustained protection for older children

The TyVOID study evaluated the long-term effectiveness of a single-dose TCV in Bangladeshi children over five years, finding high protection (80-96%) within the first two years.
Three to five years post-vaccination, the incidence of typhoid increased three-fold, especially in younger children, indicating a decline in vaccine effectiveness, with better sustained protection (59-85%) observed in children vaccinated at age two or older.
The study suggests a booster dose might be beneficial, especially for children vaccinated under age two, to ensure sustained protection through the school years when typhoid risk is highest.
With TCV scheduled for a national campaign rollout in Bangladesh in 2025, continued monitoring is essential to understand vaccine impact on typhoid burden, antibiotic resistance patterns, and vaccine duration in high-risk settings.