Estimating the cost-effectiveness of maternal respiratory syncytial virus (RSV) vaccination in Australia: A dynamic and economic modelling analysis

Background: Respiratory syncytial virus (RSV) is a major cause of respiratory illness, with younger infants at greatest risk of hospitalisation. With the recent approval of a maternal RSV vaccine in Australia, it is timely to evaluate its potential costs and health benefits in Australia. Methods: We applied an integrated dynamic and economic evaluation model to estimate specific outcomes of RSV disease and the cost-effectiveness of a year-round maternal RSV vaccination program in Australia. Cost-effectiveness was estimated using the incremental cost-effectiveness ratio (ICER) per quality-adjusted life year (QALY) gained. Results: From a healthcare system perspective, the maternal vaccination program was estimated to be cost-effective at a vaccine price less than approximately 120 Australian dollars ($AU), assuming a willingness-to-pay (WTP) threshold of $AU 50,000/QALY gained. Most of the estimated cost-savings were from preventing RSV hospitalisations in infants aged <6 months. However, while 82% of the cost-savings were from preventing RSV hospitalisations in infants aged <6 months, only about 25% of the QALY gains were in this age group. The majority of the other QALY gains came via herd effects from prevention of death in older adults and to a lesser extent, prevention of nonmedically-attended illness in older teens and adults. When predicted cost-savings and QALY gains in those >= 6 months of age were excluded, the vaccine price required to meet the assumed WTP threshold fell to $AU 63. Conclusions: A maternal RSV vaccination program in Australia could provide value for money by reducing hospitalisations and associated costs among infants aged <6 months, depending on the vaccine price. We have provided evidence that herd effects beyond the target population may be an important consideration in assessing cost-effectiveness of maternal RSV vaccination.