Hurricane Response: Vaccine Tracking

Following the destructive 2017 hurricane season, TechFlow revitalized and modernized the U.S. Virgin Islands Immunization Registry System for a more resilient future.


  • Since its implementation, the TechFlow system has helped reduce preventable disease outbreaks by enabling identification of under-vaccinated areas, leading to a better understanding of disease spread.
  • TechFlow’s innovations in modernizing the VIIRS will benefit COVID-19 vaccination surveillance and program operations once a vaccination is approved.
  • TechFlow’s VIIRS implementation helps to track and manage immunizations, which can lead to significant healthcare cost savings through reduced treatments related to preventable diseases.
  • TechFlow’s innovative cloud-based solution restored access to VIIRS data for users across 17 provider organizations and has operated with no service interruptions and 99.99% system availability, despite challenging island conditions.
  • TechFlow’s modernized VIIRS implementation was the first approved immunization registry to fully operate in the Cloud.
  • TechFlow’s VIIRS stabilized the prior WIR system through its cloud deployment. A large portion of the United States and its territories can migrate to this more stable version, providing better health services for the entire population.
  • The TechFlow team is excited to further enhance VIIRS and other IIS’ with data analytics across populations, shared insights from applied AI, and other impactful enhancements.






The one-two punch of category 5 hurricanes Irma and Maria devastated the U.S. Virgin Islands, leaving the USVI without any infrastructure to support its impacted population. After months of hard work restoring and rebuilding the bare minimum for sustenance, health issues began to resurface as a major concern.

In addition to damage across the islands, the hurricanes had completely wiped out the Virgin Islands Immunization Registry System and its infrastructure. VIIRS plays a critical role in tracking the health of the territory’s population by maintaining immunization records, identifying high-risk groups across islands and ultimately enabling health care professionals to promote and administer immunizations more effectively. VIIRS software, servers, application backups were literally all blown away by the hurricanes. This presented two immediate challenges that put a population already in crisis at further risk – the first being the restoration of the VIIRS infrastructure after it was rendered inoperable, and the second being continuity of operations and maintenance of VIIRS, whose work is critical for managing immunization coverage and disease prevention within the Virgin Islands.

As a further complication, despite efforts to quickly restore services, the US Virgin Islands was unable to recover recent or salvageable backup tapes. The VIIRS software source code, documentation and data elements obtained in recovery were outdated and incomplete, with missing functions and support components. The TechFlow team had to start almost from scratch, in cooperation with CDC and the WIR Consortium, to rebuild the system.


Rather than simply pursue the recovery and restoration of VIIRS server-based system, TechFlow saw an opportunity to bring to life a forward-leaning solution to move VIIRS into the future. By developing a cloud solution, the TechFlow team could both modernize VIIRS and provide USVI a much improved application. TechFlow’s engineers were excited as they looked to optimize the application and its architecture by leveraging the cloud to not only get the Virgin Islands back up and running quickly, but also make the application and its data hurricane-proof for a resilient future.

To get started, TechFlow had to piece together what it could about the previous software’s functionality. The TechFlow team engaged the Virgin Islands Department of Health (VIDOH), the Centers for Disease Control and Prevention (CDC) and other Wisconsin Immunization Registry (WIR) Consortium of system owners to obtain information and components that were part of the lost system. Confronting a lack of documentation and functional software, the TechFlow team embarked on an unplanned and highly technical series of reverse engineering exercises. Like putting together a puzzle, the team reverse-engineered existing code fragments, identified missing elements, determined software dependencies and modified or replaced code to create a secure and fully operational server-based IIS aligned to CDC’s Functional Standards. To facilitate cloud deployment, TechFlow created an alternative code library built for virtualization running on Amazon Web Services (AWS).

The time and intensive effort continues to pay off. The team’s ultimate success in modernizing VIIRS provided CDC with a refactored and supportable modern, virtualized immunization software product that is cloud-ready, fast to deploy, and built for the future. As TechFlow completed its technical work, the team developed extensive training for Department of Health staff members, medical providers and school nurses. TechFlow also shared materials and system documentation for use in additional future education and training, to ensure those using the system also derive significant benefit helping the USVI on its path to recovery.

In the United States, every state and territory has a similar critical need to manage immunizations to protect the public. In the USVI, TechFlow brought its “Always Ahead” approach to not just solve the challenge at hand, but also to create a solution that solves problems into the future. Immunization Registry systems are an extremely important factor in ensuring and maintaining a healthy population. In an era where we face a pandemic, TechFlow’s forward-leaning solution creates a more stable, user-centric, extensible cloud-based system that will help in the management of immunizations and improve public health.