Vaccination is one of the greatest breakthroughs in public health and remains one of the best weapons against infectious diseases. Health Information Systems (HISs) are cloud-based, population-focused and confidential public health platforms that aid the COVID-19 vaccination programme at Northern Health Australia. They established their own HIS on vaccination while CVMS was being developed. This paper uses the RE-AIM (Reach, Effectiveness, Adoption, Implementation and Maintenance) framework, based on continued involvement in the implementation of two immunisation information systems: COVID-19 Vaccination Management System (CVMS) and the in-house Northern Health System (NHS). Through engagement with various stakeholders, the author established analytical frameworks, a logic model and HIS documentary analysis from a public health perspective with an emphasis on three major HIS utility parameters. The key findings are (1) vaccination information systems promote vaccine equity among populations, (2) information systems promote improved decision-making of clinicians and government, which strengthens the health system and (3) vaccination information systems evaluate the safety and effectiveness of vaccines. Despite the challenges, the two immunisation HIS are instrumental in improving vaccination-related activities from managing and consolidating data in the booking system, AIR data compliance and adverse events reporting, are used to guide policymakers and further support public health emergency decision-making. The ideal system would centralise data exchange, submission and analysis across the whole state, provide easy accessibility to the public, and promote coordination between stakeholders for continuous improvement. However, it is worth noting that balancing requirements while setting up these large systems may imply a longer development time.