Persistence of immunity to 4 years of age following a delayed pertussis vaccine schedule in infancy

Not Applicable

Completed

• Conditions: vaccine; pertussis; immunity persistence; Inflammatory and Immune System - Other inflammatory or immune system disorders; Infection - Other infectious diseases

• Registration Number: ACTRN12622001216707
• Lead Sponsor: The Sydney Children's Hospital Network

Brief Summary

A total of 47 infants enrolled on the primary trial ACTRN12615000898550 were followed up to 4 years of age. The safety profile of the booster dose at 4 years was consistent with the known side effects of the pre-school DTaP booster vaccine. The most common side effects were pain, redness and swelling at the injection site. Systemic side effects were mild and a fever rate of approximately 7% was seen. There were no other safety concerns. The were strong immune responses to all pertussis antigens following the booster dose at 4 years of age, indicating a good response to the booster dose. Children who had evidence of pertussis antibodies at 6 weeks of age had a slightly lower immune responses to the 4 year old booster dose than children who did not have pertussis antibody at 6 weeks of age. The modified pertussis vaccine schedule was both safe and resulted in good immune responses to pertussis.

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Completion: 2019-05-22
• Study Start: 2022-09-09
• Last Update Posted: 19 September 2022

Recruitment & Eligibility

• Status: Completed
• Sex: All
• Target Recruitment: 47

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)

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
To compare surrogate measures of protection (IgG antibody) against pertussis antigens prior to and following a DTPa-IPV booster vaccine at 4 years old in children previously recruited to a study of a 3 dose alternate policy relevant pertussis vaccine schedule.<br><br>The IgG antibodies to pertussis antigens will be measured on blood sera samples collected from participants in the trial[Serology will be measured at 4 years - prior to receipt of the DTaP-IPV booster vaccine and at 4 years and 1 month 1 month after receipt of pre-school DTPa-IPV vaccine]