None listed
Conditions
Brief summary
Our First trial (ACTRN12615000898550) examined the immune responses to pertussis and other vaccine antigens following a modified infant vaccination schedule for DTPa-IPV-Hep B-Hib (Infanrix Hexa®) vaccine when given at 6 weeks, 12 weeks and 11-12 months of age. The immune responses in this study following this modified vaccine schedule will be compared to immune responses in a separate historical comparison study where Infanrix Hexa® vaccine was given at 6 weeks, 4 months, and 6 months of age), Continued study of the cohort enrolled onto ACTRN12615000898550 is a unique opportunity to examine the longer-term safety and immunogenicity at 18 to 36 months and again at 4 years old of children who followed the modified vaccine schedule and to compare their results with a historical cohort of infants who received pertussis-containing vaccines given according to the standard immunisation schedule. The key questions of prolonged immune tolerance to pertussis antigens, negative interference on concomitantly administered antigens and increased reactogenicity to booster doses following altered timing of Pa vaccination are only able to be answered by the long term follow up of our cohort. These are essential data to inform national vaccine policy and will be of considerable interest internationally. Antibody responses in the blood of children originally enrolled on ACTRN12615000898550, which are believed to correlate with protection, will be measured at (1) 18 to 36 months of age, at (2) 4 years of age pre-booster dose of DTPa-IPV vaccine and (3) 1 month after receipt of 4 year old DTPa-IPV booster vaccine. In addition, differences in immune and safety responses in the study cohort after receipt of the 4 year old booster dose of DTPa-IPV compared to historical controls who have received the existing vaccine schedule (at 6 weeks, 4 months and 6 months of age).
Interventions
Our First Phase trial examined whether a modified infant vaccination schedule for DTPaIPV-Hep B-Hib (Infanrix Hexa®) at 6 weeks, 12 weeks and 11-12 months gave similar
immune protection in the first 6 months of life in comparison to the existing vaccine
schedule (at 6 weeks, 4 months, and 6 months of age),
In this follow on study the aim is to compare surrogate measures of protection (IgG antibody) against pertussis prior to and following a DTPa-IPV booster vaccine at 4 years old in children p
Our First Phase trial examined whether a modified infant vaccination schedule for DTPaIPV-Hep B-Hib (Infanrix Hexa®) at 6 weeks, 12 weeks and 11-12 months gave similar immune protection in the first 6 months of life in comparison to the existing vaccine schedule (at 6 weeks, 4 months, and 6 months of age), In this follow on study the aim is to compare surrogate measures of protection (IgG antibody) against pertussis prior to and following a DTPa-IPV booster vaccine at 4 years old in children previously recruited in the primary alternate schedule pertussis vaccine study (ACTRN12615000898550) No additional booster vaccines were given in this study. Children enrolled on the study followed the routine immunization program at the time the study was conducted from 12 months of age onwards.
Sponsors
The Sydney Children's Hospital Network
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Prevention
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Months to 36 Months
Healthy volunteers
Yes
Inclusion criteria
Children who are between 18 to 36 months old and were subjects previously enrolled in the First Phase study (ACTRN12615000898550) are eligible to participate in this study. Eligible children must meet inclusion and exclusion criteria at the time of first visit and parents/guardians must give written informed consent.
Exclusion criteria
Contraindications to vaccination as listed in the NHMRC Australian Immunisation Handbook or as listed in the Infanrix-IPV Product Information. DTPa-IPV vaccine will not be administered to individuals known to be hypersensitive to any component of the vaccine or residues carried over from manufacture (such as formaldehyde and glutaraldehyde). Administration of immunoglobulins and any blood products within the 3 month period prior to the first visit or planned administration during the study period; in which case, a delay in enrolment will be considered in the absence of other excluding criteria. Any confirmed or suspected immunosuppressive or immunodeficient condition . History of serious chronic illness or condition which in the judgement of the clinical investigator would preclude study participation. History of neurologic disease or seizure Must not have had the vaccination scheduled for age 4 years (ie Infanrix-IPV). Must not have had a DTPa booster in the second year of life (prior to study enrolment)
Outcome results
None listed