Key clinical point: Australian adults and older children born before rotavirus vaccine availability were not immunized and may have been less likely to have multiple subclinical infections because of less virus circulation overall, so there was less immune boosting.
Major finding: Vaccine effectiveness did not decline in 2017 and thus was not likely responsible for the outbreak. Two doses of Rotarix vaccine was 73.7% effective in protecting children aged 6 months to 9 years against laboratory-confirmed rotavirus over the 8-year study period.
Study details: Vaccine effectiveness was tracked from 2010 to 2017 by analyzing 9,517 rotavirus cases in the state of New South Wales.
Disclosures: The study was funded by Australia’s National Center for Immunization Research and Surveillance, which receives government funding. The Australian Rotavirus Surveillance Program is supported by government funding and the vaccine companies Commonwealth Serum Laboratories and GlaxoSmithKline. Ms. Maguire is supported by an Australian Government Research Training Program Scholarship. One author is director of the Australian Rotavirus Surveillance Program, which received funding as above. The other study authors reported no relevant financial disclosures.