Acute lower respiratory infections (ALRIs), including pneumonia, are one of the major causes of childhood mortality and morbidity worldwide, and early childhood infection is associated with future chronic lung disease such as bronchiectasis. Maternal immunisation is a developing strategy that may protect both pregnant women and their infants. Within days of birth heavy colonisation by respiratory bacteria occurs in First Nation infants, and these bacteria can then infect the lower airways. This all occurs months before infant immunisation provides protection.

Pilot work conducted by the Team showed that infants immunized with PCV-HiD (a 10 valent pneumococcal conjugate vaccine that also offers some protection against Haemophilus influenzae) had improved immunity to H. influenzae and a lower risk of airway infection. Thus, maternal immunisation with PCV-HiD has promise in preventing ALRIs in First Nation infants.

Aim

The aim of this study is to investigate whether vaccinating pregnant First Nation mothers with PCV-HiD reduces acute lower respiratory infections in their infants during their first year if life. It is hypothesised that infants born to vaccinated mothers will have at least a 25% reduction in acute lower respiratory tract infections during their first year of life compared to those that did not receive the vaccine.

Secondary aims include:

• To evaluate the effect of maternal immunisation on the infant’s immune response
• To determine the effect of maternal immunisation on infant bacterial carriage
• To evaluate reasons why First Nation pregnant women accept or refuse vaccination

This study is funded by National Health and Medical Research Council (NHMRC).

The study is being conducted in Darwin, Central Australia, Brisbane, Logan and Kota Kinabalu in Malaysia. The study's protocol has been published https://pubmed.ncbi.nlm.nih.gov/35111703/