Comparison of acellular pertussis-tetanus-diphtheria vaccines and whole-cell pertussis-tetanus-diphtheria vaccines in infancy

Abstract

Background:In clinical trials, diphtheria, tetanus and acellular pertussis vaccines have been shown to be less reactogenic than whole-cell combination vaccines.Aim:To evaluate diphtheria and tetanus toxoids combined with acellular pertussis (DTaP) and diphtheria and tetanus toxoids combined with whole-cell pertussis (DTwP) with regard to local, systemic and febrile reactions.Methods:This prospective study was undertaken in 2008 when DTwP was replaced by DTaP in Turkey. The study population included infants of 2 (n = 1231), 4 (n = 1294), 6 (n = 1324) and 18 (n = 734) months of age who had received DTaP or DTwP vaccines between 2003 and 2008. Local, systemic and febrile adverse events were monitored by parental observation and recorded on a diary card.Results:Altogether, 1422 children were vaccinated, 45·2% of whom were male. 4583 doses of DtaP and 198 of DTwP were administered. Local, systemic and febrile reactions were more commonly observed in infants who received DTwP vaccines than in those who received DTaP vaccines (9·09% vs 0·85%, 12·12% vs 1·00% and 26·26% vs 2·58%, respectively, P<0·001). Infants who received DTaP vaccines at 2 months of age had systemic reactions (n = 24, 1·9%) more frequently than those at 4 (n = 12, 0·92%, P<0·001), 6 (n = 8, 0·6%, P<0·001) and 18 months of age (n = 1, 0·13%, P<0·001). Infants who received DTaP vaccination at 4 months of age had febrile reactions (n = 52, 4%) more often than those at 2 (n = 21, 1·7%, P<0·001), 6 (n = 37, 2·7%, P<0·001) and 18 months of age (n = 6, 0·81%, P<0·001). No difference in local reactions associated with number of vaccines was observed in the DTaP group. There was no significant difference in the rates of local, systemic and febrile reactions between the different age groups of children who received DTwP.Conclusions:DTaP vaccines were found to have fewer local, systemic and febrile reactions than DTwP vaccines.