What new information is provided by a multicentric Indian study which concludes that dTPa (Boostrix) is safe and well-tolerated at age 4-6 years?(1) It is well known that DTP is safe and well tolerated at this age. Reducing the dose of diphtheria toxoid and replacing whole cell pertussis vaccine (Pw) by acellular pertussis vaccine (Pa) is not going to make it unsafe or less tolerable to children.

The IAP Immunization Schedule recommends the use of DTP at 4-6 years of age while the GOI Schedule recommends DT; no international immunization schedule recommends low-dose diphtheria toxoid (2 Lf) at this age. So the pertinent point is whether a vaccine that contains low-dose diphtheria toxoid is effective against diphtheria when administered at this age. Antibody levels to diphtheria toxoid are known to correlate with efficacy; unfortunately the study does not mention antibody levels before and after the administration of dTPa. Until this information is available, it is unethical to use this vaccine as a booster at 4-6 years of age.

Newton Luiz,
Dhanya Mission Hospital,
Potta PO, Thrissur, Kerala 680 722, India.
E-mail: [email protected]