Optimising pertussis vaccination in infants: a new approach. Effects of delaying the third pertussis vaccine to 11 months old.

Phase 4

Completed

• Conditions: Immunogenicity and safety after pertussis vaccination; Inflammatory and Immune System - Normal development and function of the immune system; Respiratory - Other respiratory disorders / diseases; Infection - Other infectious diseases

• Registration Number: ACTRN12615000898550
• Lead Sponsor: The Sydney Children's Hospitals Network

Brief Summary

The 2 +1 acellular pertussis combination vaccine schedule was safe and immunogenic. Pertussis antibody levels were lower after the second dose in the 2+1 schedule when measured at 6 months of age compared to the 3+0 schedule. This could be related to the earlier administration of the second dose at 12 weeks of age in the 2+1 schedule, and the fact that there was longer interval post dose 2 where the blood sample was collected (3 months after dose 2 in the 2+1 schedule compared to 2 months after dose 2 in the 3+0 schedule). As is known, the presence of pertussis antibodies at baseline (due to maternal transfer) negatively impacts the infant response to acellular pertussis vaccines in infancy. This was seen in both the 2+1 and 3+0 vaccine schedules. Delaying the 3rd dose to 12 months of age (as seen in the 2+1 schedule) results in higher antibodies compared to receipt of the 3rd dose at 6 months (3+0) schedule. A limitation is the fact that antibody levels for pertussis, diphtheria and tetanus were measured in different laboratories using different techniques: MIA at Telethon Kids Institute for the 2+1 schedule and ELISA at GSK laboratories for the 3+0 schedule. The assay at the Telethon Kids Institute is able to quantify absolute values above (no lower limit of detection).In the context of maternal Tdap vaccination the 2 +1 vaccine schedule is a potential safe and immunogenic vaccine schedule which could avoid the need for an additional DTPa booster in the second year of life.

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2015-08-27
• Study Completion: 2017-07-30
• Last Update Posted: 15 August 2022

Recruitment & Eligibility

• Status: Completed
• Sex: All
• Target Recruitment: 85

Inclusion Criteria

Eligible infants of English-speaking parents must be healthy (by history and physical examination) at the time of the first vaccine, born at 36 completed weeks gestation or greater, between 6-7 weeks of age at the time of enrolment, and whose parents give written informed consent.

Exclusion Criteria

Infant has received the 6 week old vaccines.

Contraindications to vaccination as listed in the current NHMRC Australian Immunisation Handbook (at time of study 10th edition, online access http://www.health.gov.au/internet/immunise/publishing.nsf/Content/Handbook10-home). The relevant 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).

Infant of a mother known to be a carrier of hepatitis B virus.

Administration of immunoglobulins and any blood products preceding the first dose of study vaccine or planned administration during the study period.

Any confirmed or suspected immunosuppressive or immunodeficient condition, in child.

Major congenital defects or serious chronic illness.

Neurologic disease or seizure.

Study & Design

• Study Type: Interventional
• Study Design: Not specified