Delayed immunisation is a specific risk factor for admission to hospital with pertussis rather than being a marker of infants at increased risk of admission to hospital for any acute respiratory illness. Improving on-time delivery of immunisations can be expected to decrease the admission rate for pertussis in New Zealand
Parents often ask if it's ok to delay immunizations "until they are older and the immune system is stronger." It's important to listen to these concerns so that parents know that we're hearing them. Yet it's also important to inform them of the science that causes us to suggest the recommended schedule. This short paper from New Zealand reminds us of the importance of "immunising" infants appropriately.