JAMA   
August 01, 2012, Vol 308, No. 5
http://jama.ama-assn.org/current.dtl

Research Letters | August 1, 2012
Number and Order of Whole Cell Pertussis Vaccines in Infancy and Disease Protection
Sarah L. Sheridan, BMed, MAppEpid; Robert S. Ware, PhD; Keith Grimwood, MB, ChB, MD; Stephen B. Lambert, MBBS, PhD

To the Editor: Due to their lower rate of adverse events, acellular pertussis vaccines (diphtheria-tetanus-acellular pertussis; DTaP) replaced whole cell vaccines (diphtheria-tetanus-whole cell pertussis; DTwP) in many developed countries during the 1990s. DTaP became available in Queensland, Australia, in 1996 and replaced DTwP for publicly funded primary course immunizations delivered at ages 2 months, 4 months, and 6 months in March 1999. This meant children born in 1998 could receive a primary course consisting of only DTwP, only DTaP, or a mixed schedule…