Risk Groups for Vaccine Preventable Respiratory Infections in Children and Adults: An Overview of the Australian Environment

Respiratory infections are a leading cause of sickness and death in Australia. In Australia, an adult- and pediatric-funded immunization program has been established for the prevention and control of vaccine preventable respiratory infections (VPRI), including pneumococcal disease (PD), influenza A/B, respiratory syncytial virus (RSV) infection, and COVID-19. This narrative review outlines the current Australian adult and pediatric immunization guidance for VPRIs and the literature underlying current risk group recommendations, including the clinical and economic burden of VPRIs, vaccination effectiveness, and coverage. Gaps in current risk group definitions, as well as additional risk groups that could be included in vaccine recommendations, are also discussed. Further research is needed to determine the optimum age for vaccination in adults which may enable alignment of age recommendations across different VPRIs. The presence of multiple risk factors, known as risk stacking, has been shown to increase the risk of severe disease for several VPRIs emphasizing the importance of vaccinating individuals with multiple risk factors. Further research is necessary to determine the effectiveness of vaccines in older adults and to develop more effective vaccines for high-risk pediatric groups, such as those with compromised immunity or for children who have undergone hematopoietic stem cell transplantation.