Failure of adolescent booster responses to tetanus toxoid despite infant immunization.

ECDC comment

The aim of this study was to assess the capacity of a tetanus toxoid booster to reactivate infant-triggered immunity.

Posfav-Barbea et al. – June 2010 – Vaccine 2010; 28: 4356-4361.  Frequent failure of adolescent booster responses to tetanus toxoid despite infant immunization: Waning of infant-induced immune memory

The aim of this study was to assess the capacity of a tetanus toxoid booster to reactivate infant-triggered immunity. To define that, anti-tetanus antibodies were assessed before and after boosting 162 adolescents and 219 children from Mfou (Cameroon). Among 63 adolescents with 3 recorded dose of infant DTP, 29/63 (46%) responded with a ≥4-fold increase of antibody titers, 35/63 (55%) reaching the 0.10 UI/ml threshold. Response rates were slightly higher (62%) in children aged 10–11 years. Responders and non-responders only differed significantly in their baseline anti-tetanus antibodies.

Disclosure statement: The study was supported by Children Action, a charitable foundation for disadvantaged children throughout the world, and by university research funds of the WHO Collaborating Center for Neonatal Vaccinology.  Two of the authors have received honoraria and research grants from various vaccine manufacturers, but none related to this work. All other authors declared no conflict of interest.

ECDC comment, 7 June 2010: This study demonstrates that infant immunization in absence of childhood boosting does not result in the long-term persistence of anti-TT immune memory. This result supports the WHO recommendation to implement childhood and adolescence DTP boosters.