Australia's child immunisation rate hits record highData shows the ratio of Australian five-year-olds who are fully immunised hit a new high in the September quarter.SBS Explains: What is herd immunity?Published 24 October 2018 2:41pmUpdated 24 October 2018 2:45pmBy Peyman JamaliAvailable in other languagesSkip to article contentShare this with family and friendsCopy linkShareShare