Effectiveness of COVID-19 vaccines against hospitalisation, death and infection over time in Aotearoa New Zealand: a retrospective cohort study

Accurately evaluating vaccine effectiveness (VE) and subsequent VE waning (understanding when VE declines) helps to inform public health decision making during an evolving pandemic. Understanding the waning of VE after the first, second and booster vaccine doses can also help identify who is most likely to benefit from further booster doses or other vaccines or interventions to reduce risk.