Safety and immunogenicity of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-pertussis (DTP) combination vaccine administered in a dual-chamber syringe to infants in Belgium and Chile

Lot-to-Lot Consistency of a Combined Hexavalent Diptheria-Tentanus-Acellular-Pertussis, Hepatitis B, Inactivated Polio and Haemophilus b Conjugate Vaccine, Adminstered to Healthy Chilean Infants at 2, 4 and 6 Months of Age

“…Such a trend was not observed in French and German infants, 8,40 but was previously reported in Chilean infants for the local reactions to a DT-acellular pertussis vaccine combined or concurrently administered with PRP-T. 22 Nevertheless, the rates of fever >38˚C, of local reaction, and of solicited systemic adverse events, such as irritability/crying and vomiting/diarrhoea were definitively much lower (three to four times lower) than those reported with a DT whole-cell pertussis vaccine reconstituted with PRP-T in Chilean infants. 10 In summary, this study showed that the liquid hexavalent combined vaccine induced satisfactory immune responses to all antigens, yielding seroprotection rates greater than 95% for HB and Hib and equal to 100% for D, T and the three types of polio viruses. The effective antibody response to HB, both in terms of GMT and seroprotection rates, may indicate that the liquid hexavalent combined vaccine could be included in the national immunization schedule of countries where the endemicity of hepatitis B is low.…”

“…For tetanus and diphtheria, the seroprotection rates and GMTs were of the same magnitude as those described elsewhere with this hexavalent vaccine, or with combinations containing fewer antigens. 8,10,27 GMTs of anti-PRP antibodies were lower than those observed in a study on interactions between DTaP, IPV and Act-HIB ® vaccines in Chilean infants; 27 however, more than 97% of the infants reached seroprotective levels of anti-PRP antibodies (>0.15 µg/mL). This seroprotection rate after three doses of PRP-T is as high as those previously reported in Chilean infants, 31,32 and the GMTs were greater than the ones measured with the same vaccine in French infants.…”

“…8 The markedly greater immune response to PRP-T in Chilean infants versus North American or European infants has been observed consistently. 10,27,[31][32][33] In early studies, 25% of Chilean infants reached a concentration >1.0 mcg of PRP antibody per ml of serum after the first primary dose of vaccine. [31][32][33] A case/control study undertaken to try and identify factors associated with this robust serologic responses revealed that infants who mounted such enhanced responses came from significantly lower socioeconomic level households than the other infants, and their parents had less education.…”

“…8,9 Earlier experience with DTP-PRP-T or DTaP-IPV/PRP-T showed that Chilean infants had higher local reaction rates and higher antibody responses to PRP than European infants. 10 The present study represented the first time that the safety and immunogenicity of the liquid hexavalent combined vaccine was evaluated in a nonEuropean infant population. Three manufacturing lots were used and compared for consistency of immune responses.…”

Immunologic response to Hib tetanus toxoid conjugated vaccine coadministered with DTPa either mixed or in two separate injections in toddlers not primed with Hib vaccine

“…4,17,18 Secondly, differences in vaccine differences in vaccine responses between populations have been reported before; children from less industrialized countries appear to have higher anti-PRP anti-PRP and anti-TT antibody titers than those from developed western antibody titers than those from developed western countries. 19,20 The fact that environmental factors play an important environmental factors play an important Grade 3: pain, cries when limb is moved; redness and swelling, diameter >20 mm; fever (axillary temperature) >39.0°C; fussiness, persistent crying and cannot be comforted; all other symptoms, preventing normal activity.…”