Reactogenicity and safety of DTPa vaccine and Haemophilus influenzae type b conjugate vaccine (Hib) in a single injection vs DTPw and Hib as separateinjections as a booster vaccination in 18-month-old children

Objective: To compare the reactogenicity and safety of the administration o f diphtheria-tetanus-acellular pertussis (DTPa) and Haemophilus influenzae type b conjugate (Hib) vaccines in one injection with those of the simultan eous administration of diphtheria-tetanus-whole cell pertussis (DTPw) and H ib vaccines in opposite limbs as booster doses to 18-month-old children pre viously primed with three doses of DTPw and Hib vaccines as a primary vacci nation course. Design and Setting: Nonblind, prospective, randomised, multicentre comparat ive study set in Spain. Patients and Participants: 216 children (17.2 +/- 0.99 months old). Methods: Children were randomised to receive DTPa/Hib (group 1; n = 111) or DTPw + Hib (group 2; n = 105) and were followed for up to 30 days post-vac cination. All children received oral polio vaccine concomitantly. Local and general symptoms were recorded by parents on diary cards. Results: The incidences of any solicited local reaction and any solicited g eneral symptom 'probably related' or 'suspected to be related' to Vaccinati on were statistically significantly higher (p < 0.0001) in group 2 than in group I. Pain at the injection site was the most commonly reported local re action, both in terms of any pain (40% in group 1; 89% at the DTPw site in group 2; p < 0.0001) and in pain that caused the child to cry when the limb was moved (1% and 42%; p < 0.0001). Any redness or swelling were significa ntly more common (p < 0.0001) at the DTPw injection site (71% and 60%, resp ectively) than at the DTPa/Hib site (34% and 27%). Fever (rectal temperatur e greater than or equal to 38 degreesC) was recorded for 10% and 56% of par ticipants in groups 1 and 2, respectively (p < 0.0001). Only one case in gr oup 1 and three cases in group 2 had fever >39.5 degreesC. Fussiness (group 1: 28%; group 2: 71%), loss of appetite (15% and 37%, respectively), and r estlessness (16% and 34%, respectively) were also statistically significant ly more frequent (at least p < 0.003) in DTPw + Hib recipients. Analgesics/ antipyretics were prescribed as prophylactic treatment in only <8% of cases ; however, antipyretics were significantly more often prescribed (p < 0.000 1) after vaccination in group 2 children (46%) than in group 1 children (6% ). Unsolicited symptoms were recorded for 33 participants, including 22 cas es [group 1: one case; group 2 (DTPw limb): 21 cases] of lameness that reso lved within 1 to 5 days (median 1 day). Conclusions: Administration of DTPa/Hib in one injection leads to better re actogenicity and safety profiles than the administration of DTPw + Hib as t wo injections as booster doses to 18-month-old children primed with DTPw an d Hib vaccines.