From legacy systems to real-time response: VPD-SMART implementation and its impact on public health surveillance in Paraguay and the Americas.

In the Americas, traditional public health surveillance systems often face a significant data-use gap, hindering a timely response to vaccine-preventable diseases (VPDs). This manuscript details the implementation of VPD-SMART, a novel DHIS2-based system, as a digital transformation initiative to enhance VPD surveillance and bridge this gap. We analyze Paraguay's transition from the legacy Integrated Surveillance Information System (ISIS) to VPD-SMART, focusing on how its functionalities, including real-time decentralized data collection and enhanced analysis, improve the performance of health information systems. We find that the transition to VPD-SMART significantly improved data quality, consistency, and timeliness. A quantitative analysis showed a notable increase in data completeness and a rise in consistency for key variables from 54 % to 97 %. The average time for data entry also decreased, shifting from a weekly to a daily basis. Qualitative findings confirm that the system empowers health authorities with real-time, data-driven insights. By examining these challenges and opportunities, we provide empirical evidence on how leveraging DHIS2 can enhance public health surveillance and inform similar digital transformation efforts in other low- and middle-income countries.