The pediatric formulations usually have
3-5 times as much of the diphtheria component than what is
in the adult/adolescent formulation. Similarly, the
formulations for adults/adolescents have around one third of
acellular pertussis content than pediatric formulations. The
amount of tetanus toxoid in each of the products remains
almost equivalent. Dose reduction for diphtheria and
pertussis is necessary because of the increased incidence of
local and systemic reactions particularly to diphtheria
toxoid and to some extent to acellular pertussis component
in older children and adults [1-4].
On the other hand, the immune response to
tetanus toxoid appears to decrease with increasing age. In
comparative studies, children generally will develop higher
levels of antitoxin than adults [5]. These are the reasons
why dose of tetanus toxoid is not reduced in adult
formulations.
Vipin M Vashishtha
Convener, IAP Committee on Immunization,
Email:
[email protected]
References
1. Plotkin SA, Orenstein WA, Offit PA
(Ed). Vaccines. 5th ed. Philadelphia: Saunders Elsevier;
2008.
2. Simonsen O, Kjeldsen K, Vendborg H-A,
Heron I. Revaccination of adults against diphtheria I:
responses and reactions to different doses of diphtheria
toxoid in 30-70-year-old persons with low serum antitoxin
levels. Acta Pathol Microbiol Immunol Scand. 1986;94:213-8.
3. Keitel WA, Muenz LR, Decker MD,
Englund JA, Mink CM, Blumberg DA, et al. A randomized
clinical trial of acellular pertussis vaccines in healthy
adults: dose-response comparisons of 5 vaccines and
implications for booster immunization. J Infect Dis.
1999;180:397-403.
4. McComb JA, Levine L. Adult
immunization II. Dosage reduction as a solution to
increasing reactions to tetanus toxoid. N Engl J Med.
1961;265:1152-3.
5. Myers MG, Beckman CW, Vosdingh RA, Hankins W. Primary
immunization with tetanus and diphtheria toxoids: reaction
rate and immunogenicity in older children and adults. JAMA.
1982;248:2478-80.
