Impact of rotavirus vaccination in Australia

Abstract

Rotavirus is the major cause of gastroenteritis in young children worldwide, resulting in >500 000 deaths annually. In an effort to reduce the disease burden two live oral rotavirus vaccines were developed: Rotarix a monovalent vaccine and RotaTeq a pentavalent vaccine containing five human-bovine reassortant strains. Both vaccines were introduced into the Australian National Immunisation Program in July 2007. Each state and territory health agency has independently selected the rotavirus vaccine to include in its immunisation schedule. Studies from multiple Australian states have shown that emergency room visits and hospitalisation for rotavirus have declined dramatically since vaccine introduction. Studies have been conducted comparing the impact of the different vaccines on the circulating rotavirus strains. Differences in the prevalence of genotypes G2P[4] and G3P[8] were identified between states, while rare genotypes have recently been identified as a minor cause of disease in Australian children. Vaccine introduction has resulted in a dramatic decline in the rates of severe rotavirus disease. Since vaccine introduction, changes have been demonstrated in circulating strains. This likely reflects the natural annual fluctuations in strain prevalence rather than a lack of vaccine protection. Additional studies are required to determine the longer-term impact of vaccine introduction on circulating strains.