Effect of COVID-19 restrictions and border closures on vaccine preventable diseases in Victoria, Australia, 2020–2021

Background In 2020, Victoria introduced multiple interventions aimed at containing the spread of coronavirus disease 2019 (COVID-19). We examine the effect of these restrictions on other vaccine preventable diseases (VPDs). Methods We analysed the mandatory reporting data, notified to the Victorian Department of Health, for VPDs from January 2015 to December 2021. Results Reductions in notifications were seen for most notifiable VPDs. A precipitous decline in influenza and measles notifications was recorded in April 2020, which was sustained for both diseases throughout 2020–2021. Notifications for chickenpox, invasive meningococcal disease, invasive pneumococcal disease, and pertussis were reduced by greater than 50% from the 2015–2019 average. No notified cases of diphtheria, poliomyelitis, or rubella were reported in 2020-2021. Conclusion Restrictions placed to mitigate the effects of the COVID-19 pandemic were associated with significant reductions in other VPDs, which were sustained into 2021. Nevertheless, it is important that high levels of population vaccine coverage continue, to prevent a rebound increase in VPDs as restrictions are eased, and to maximise protection against VPDs for all Australians.