How to participate

If you are interested in participating in this study, please visit the OPTIMUM study website for more information

Study short name

OPTIMUM: OPTimising IMmunisation Using Mixed schedules

Study full name

A double-blind, randomised, controlled trial to compare allergic outcomes in children following vaccination with acellular pertussis antigen given at 2 months of age versus whole cell pertussis in the infant vaccine schedule

Principle Investigator

Tom Snelling

Administering Institute

National Health and Medical Research Council (NHMRC) and WA Child Research Fund

Major funding source

National Health and Medical Research Council (NHMRC)

Study focus


Study design


Main study aim

To investigate if giving a dose of ‘whole-cell’ whooping cough vaccine between 6 and 12 weeks of age, instead of the ‘acellular’ whooping cough vaccine can help protect against allergy.

Additional study information

More Australian children are developing food allergies, particularly since the late 1990s. To understand why, we looked at what else changed at that time. One thing was the whooping cough vaccine. The old vaccine was replaced by a new one. Children are given several doses of whooping cough vaccines when they are young. We believe children who receive one dose of the old vaccine will be less likely to develop food allergies. We want to test this by comparing two groups of children. In the OPTIMUM study, half of the babies will receive the ‘whole-cell’ whooping cough vaccine, and the other half will receive the ‘acellular’ whooping cough vaccine at two months of age.

Study population

Infants, aged 6-12 weeks, who have not yet received their 6-8 week vaccines.

Study status

Recruitment ongoing, through June 2023.