Abstract The main purpose of this study was to provide an efficient, convenient and a systematic processing of COVID-19 vaccination among residents being catered by the Rural Health Unit of the Municipality of Estancia, Iloilo. As such, this paper aimed to design and developed a web-based immunization information system with SMS support that would meet user requirements, determined the extent of usability in terms usefulness, satisfaction, ease-of-use of system prototype as perceived by the residents and health personnel, and determined the degree of quality of the proposed system based on ISO/IEC 25010:2011 Systems and Software Quality Requirements and Evaluation Quality Model as perceived by expert evaluators. A total of forty-seven (47) respondents participated in the study. Developmental and descriptive research designs were employed in this study to systematically develop the system product and to describe the observation of the respondents based on the set objectives. Likewise, the Rapid Application Development Model was used in the development of the system prototype. The mean statistics were employed to describe the extent of usability and degree of quality of the system prototype. Findings showed that the levels of usability, as perceived by both residents and health personnel, was described as very good. On the other hands, the degree of quality of the system prototype was viewed by the expert evaluators as good.