A study by Bose, et al.(1) regarding DTPa and a study by Bavdekar, et al(2) regarding DTPw merit some pertinent observations.

Both studies concluded that the vaccine is safe and well tolerated by the Indian infants or the Indian pre-school children. Authors of the DTPa study also conclude that: "though no direct comparison has been made with DTPw vaccine in the current study, the observed adverse effect profile appears to be better than that reported with DTPw vaccine in this age group"(1). However, the occurrence of pain was similar in both studies; swelling was lesser in the DTPa group. The differences could be attributed to different muscle mass in different age groups in the 2 studies and the quantity of pertussis in the two vaccines. Thus, the assertion by Bose, et al.(1) does not appear conclusive.

One more point which needs attention is that DTPa has reduced quantity of diphtheria and pertussis antigens. Such a vaccine is recommended for adolescents and adults and not for preschool children. Studies done in pre-school children in Thailand, Taiwan and United Kingdom cited by authors(1) have been published between 2003 and 2005. Followup of these children will tell if reduced quantities of diphtheria and pertussis antigens provide long term protection. The Committee on Infectious Diseases of American Academy of Pediatrics states that minimum age for Boostrix is 10 years and for Adacel Vaccine 11 years which have reduced quantities of diphtheria and pertussis components(3).

Yash Paul,
A-D-7, Devi Marg, Bani Park,
Jaipur - 302016, India.
E-mail : [email protected]