Interchangeability of two diphtheria and tetanus toxoids, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b conjugate vaccines as a fourth dose in 15-20-month-old toddlers.
BACKGROUND
Since 1998, all children in Canada have been immunized with a pentavalent diphtheria and tetanus toxoids, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b conjugate vaccine (DTaP-IPV-Hib) produced by one manufacturer (Pentacel). Recently, another DTaP-IPV-Hib (Infanrix-IPV-Hib) became available. Data on the interchangeability of these products was lacking.


METHODS
In this multicentered, observer-blind study, healthy 15-20-month-old children previously immunized with three doses of Pentacel were randomly allocated to receive a single dose of Pentacel or Infanrix-IPV-Hib. Adverse events were documented by diary for 7 days post-immunization and unsolicited adverse events were documented for 30 days.


RESULTS
433 participants were enrolled (mean age 17.1 months). Rates of fever, anorexia and irritability were similar in both groups. Injection-site redness >20 mm (11.5% versus 5.6%; p = 0.038), injection-site pain (52.1% versus 39.4%; p = 0.009) and moderate or greater drowsiness (13.8% versus 7.4%; p = 0.042) were more common after Pentacel than Infanrix-IPV-Hib. The proportions of participants who were sero-protected or who sero-responded were similar for all antigens. Geometric mean titers or concentrations were similar for antibodies against diphtheria toxoid and poliovirus type 3. Geometric mean concentrations or titers were higher in the Infanrix-IPV-Hib group against pertussis toxin (88.5 EU/mL versus 65.6 EU/mL), filamentous hemagglutinin (207.3 EU/mL versus 132.1 EU/mL), pertactin (251.9 EU/mL versus 166.9 EU/mL) and poliovirus type 1 (1293.7 versus 976.2 reciprocal dilution). Geometric mean titers or concentrations were higher in the Pentacel group against H. influenzae type b (29 microg/mL versus 19 microg/mL), tetanus toxoid (5.6 IU/mL versus 4.7 IU/mL) and poliovirus type 2 (1437.3 versus 1134.2 reciprocal dilution).


CONCLUSIONS
A booster dose of Infanrix-IPV-Hib after three priming doses of Pentacel is well-tolerated and immunogenic in 15-20-month-old toddlers and can be used interchangeably.
Halperin
Scott A
SA
Clinical Trials Research Center, Dalhousie University and the IWK Health Centre, 5850/5980 University Avenue, Halifax, Nova Scotia, Canada B3K 6R8. scott.halperin@dal.ca
Tapiero
Bruce
B
Law
Barbara
B
Diaz-Mitoma
Francisco
F
Duval
Bernard
B
Langley
Joanne M
JM
Elrick
Donald B
DB
Jacquet
Jeanne-Marie
JM
D000855:Anorexia; D000907:Antibodies, Bacterial / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002170:Canada; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D005334:Fever; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D007508:Irritable Mood; D022401:Meningococcal Vaccines; D011054:Poliovirus Vaccine, Inactivated; D016037:Single-Blind Method; D012871:Skin Diseases; D012894:Sleep Stages; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
D000907:Antibodies, Bacterial; D000914:Antibodies, Viral; C500334:DT5aP-Hib-IPV vaccine; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines; D022401:Meningococcal Vaccines; D011054:Poliovirus Vaccine, Inactivated; D017778:Vaccines, Combined; D018074:Vaccines, Conjugate