Persistence of immune responses 5 years after vaccination with a single dose of typhoid conjugate vaccine (TCV) in Nepalese children.
VaccineSep 5, 2026 (epub)
Dikshya Pant, Yiyuan Zhang, Francesca Feaheny et al.
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In 30 seconds
This randomized controlled trial assessed the persistence of immune responses to a single dose of typhoid conjugate vaccine (TCV) in 20,019 Nepalese children over five years. The study found that the geometric mean concentration (GMC) of anti-Vi IgG was 109.3 at Year 5, with 88% of participants maintaining a ≥4-fold rise from baseline.
Key findings
- The GMC of anti-Vi IgG was 109.3 at Year 5 post-vaccination.
- 88% of participants maintained a ≥4-fold rise in anti-Vi IgG at Year 5.
- Antibody decay was slower in older children and those with detectable baseline anti-Vi IgG.
Why it matters
Understanding the duration of immunity following vaccination is crucial for public health strategies, particularly in endemic regions. This study highlights the long-term effectiveness of TCV, which may inform vaccination schedules and booster recommendations.