A paediatric ‘immunity debt’ has been blamed for a recent spike in pertussis, with more than 300 cases reported in Australia across all age groups since 1 January.

Infectious diseases paediatrician Professor Robert Booy says reduced immunity from a lack of exposure to respiratory infections has been behind the uptick in notifications since late 2023.

“We are dealing with a lot of pertussis at the moment,” he told AusDoc.

“It is part of the ‘immunity debt’ that we are paying. We have not had a real peak in pertussis in Australia since 2015-16, so there has been a long time between outbreaks.”