The preservation of the vaccine cold chain is crucial in order to ensure the proper preservation of vaccines throughout transport in a controlled environment. Maintaining the vaccine at suitable temperature and humidity levels during transportation will significantly significantly impacts vaccine effectiveness and quality. However, exposure to high temperature or improper conditions will result in vaccine degradation and public health concerns. Moreover, centralized real-time monitoring systems often suffer from issues related to integrity, transparency, availability, and single points of failure. This paper aims to transition data infrastructure from centralized to decentralized to enhance confidentiality, integrity, and availability (CIA). The proposed system, InoculLedger, employs IOTA and smart contracts to monitor and control environmental parameters, taking into account the vaccine's manufacturing process until the patient receives it. The system ensures transparency at every stage the vaccine undergoes and disseminates this information to all stakeholders, including the patient. The system utilizes IOTA for data infrastructure and employs smart contracts for data management. Additionally, the proposed system uses the Internet of Things (IoT) to monitor environmental parameters in real time.