As COVID-19-related immunity wanes and more transmissible SARS-CoV-2 variants of concern continue to emerge, future vaccination booster strategies must be examined.

We applied an individual-based COVID-19 transmission model to identify the preferred frequency, timing, and target groups for vaccine boosters to reduce the public health burden and health systems risk.

We found that COVID-19 boosters should be provided for all those eligible 3–4 months ahead of peak winter season at least over the next 2 years whether or not new variants of concern emerge.

Conversely, since those most vulnerable (those aged 60 years and older or those living with comorbidities) are most likely to require hospitalisation following SARS-CoV-2 infection, we found that more hospitalisations could be averted per booster dose through annual boosting of those most vulnerable versus boosting all eligible; however, only boosting the vulnerable group is unlikely to ensure reduced stress on health systems.

Future booster strategies must also consider the vaccine-induced immune-evading capacity of existing and new variants to first-generation COVID-19 vaccines and to next-generation vaccines as they become available.