Japan's COVID-19 Vaccine Center Locator

Introduction

In response to one of the most significant global health emergencies in recent history, we developed an interactive web application to help residents across Japan quickly and confidently locate COVID-19 vaccination sites. This demonstration app leverages a unified dataset of over 35,000 verified vaccination locations, enhanced with Google Maps Platform APIs to provide real-time, intuitive tools that promote vaccine accessibility and public health engagement.

Project’s Inspiration & History

The inspiration for this project stemmed from the urgent need for reliable, accessible information during Japan’s COVID-19 vaccination campaign. Fragmented government records created a challenge in helping citizens navigate vaccine availability.

To address this, the Navagis team developed a clean, verified, and unified dataset consolidating over 35,000 COVID-19 vaccination sites across Japan. This solution resolved a critical data infrastructure challenge and became a key asset for Japan’s public health response.

Building on this foundation, we developed a demonstration app to showcase how centralized data and intuitive design can significantly enhance public access and usability. Our goal is to provide a blueprint for leveraging location intelligence to enhance public health services through accessible technology.

Project Overview: What it does

Objective:

Clear and Comprehensive Visualization: Offers a seamless, interactive map rendering the entire verified dataset, allowing effortless exploration of vaccination sites.
Dynamic Proximity Search: Automatically detects and displays the user's location in real-time, quickly identifying the nearest vaccination centers.
Targeted Vaccine Filtering: Enables powerful and detailed filtering by vaccine manufacturer (e.g., Pfizer, Moderna) and types, including specific formulations suitable for children or targeting SARS-CoV-2 variants.
Visual Location Confirmation: Utilizes Google Maps Places API to show recent images of selected vaccination sites, enhancing user confidence and clarity.
Actionable Routing: Integrates Google’s Routes API to calculate and present optimal travel routes from a user's current location directly to chosen vaccination sites, providing immediate navigational assistance.

Target Audience:

General public users seeking fast, accurate access to vaccine site information
Public health administrators and policymakers looking for effective digital response tools
Developers and technology professionals exploring location intelligence applications for public health.

How We Built It: Technologies Used

React
Google Maps JavaScript API
Google Maps Places API (new)
Google Maps Routes API

Google Maps Platform Usage

1. Maps JavaScript API: The Maps JavaScript API served as the foundation of our interactive web map. It enabled us to:

Render a large dataset of geocoded vaccine locations as dynamic markers.
Utilize custom marker styling and clustering techniques to enhance usability and performance across varying zoom levels.
Integrate user interaction logic, such as hover states, clickable infowindows, and dynamic data updates, as users filter or search for locations.

Reason for Selection: This API was selected for its performance, flexibility in handling large volumes of data points, user-friendly interactions, and extensive documentation. These capabilities ensured a seamless experience for end-users exploring vaccination options in real-time.

2. Places API (New): The Places API enriched our application by providing real-world context to the displayed locations, enhancing user trust and confidence. Specifically, it enabled:

Retrieval of detailed location metadata such as place names, addresses, and contact details for individual vaccination sites.
Displaying up-to-date facility photos directly from Google Maps, providing visual confirmation and reducing uncertainty when users select a vaccination location.
Cross-validation and enhancement of our internally maintained dataset, helping resolve inconsistencies and verify data accuracy through Google’s authoritative location data.

Reason for Selection: We chose the Places API because it significantly increased user confidence by confirming the physical appearance and legitimacy of vaccination centers, which was especially critical during a public health emergency when misinformation could undermine trust.

3. Routes API: The Routes API was integrated to transform static data points into actionable pathways, enabling users to confidently reach their vaccination destination. Its integration allowed for:

Calculation of optimal turn-by-turn travel routes from the user's current location to the selected vaccination site.
Dynamic updates of route suggestions based on real-time travel conditions, providing flexible transit, driving, or walking directions.
Interactive visualization of routes directly on the map interface, offering clear navigation guidance without leaving the application.

Reason for Selection: This API was chosen because converting location insights into immediate, actionable navigation significantly enhanced the practical value of our tool, ensuring users could easily act upon the information provided by the application.

Key Learnings

Foundational Data Quality

We learned that high-quality, validated data is the foundation of any successful public-facing map solution. Inaccurate location data could mean someone misses a vaccine appointment or arrives at the wrong facility—so getting this right was non-negotiable.

Human-in-the-Loop Address Verification

To resolve discrepancies across multiple public datasets, we implemented a human-in-the-loop workflow using Google Maps search and imagery. This allowed our team to verify over 35,000 vaccination site addresses, significantly improving data reliability and public trust.

Rapid Development with Open Source

Using the Google-supported open-source react-google-maps library, we built a responsive and user-friendly interface in record time. This accelerated launch and ensured we could deliver critical location services during peak demand.

Actionable Navigation via Routes API

By integrating the Routes API, we transformed static map points into real-world destinations. Users could immediately get directions to the nearest verified site—removing friction and increasing accessibility in underserved areas.

Trust Through Visual Verification

We leveraged the Places API to display real-time images of vaccination sites, providing users with visual confirmation and building confidence that they were headed to the correct location.

Key Differentiators

Strategic Data–UI Integration

We combined a verified, nationwide vaccination dataset with a responsive, map-centric frontend powered by Google Maps Platform. This seamless integration—built using react-google-maps—transformed complex public health data into an intuitive experience, guiding people to the right care at the right time.

Purpose-Built Features for Public Health

Every feature—especially granular filtering by vaccine type, age group, and eligibility—was designed to solve real-world challenges. The app empowered users to make informed decisions during the pandemic, from finding pediatric vaccines to locating updated doses for new variants.

End-to-End Location Intelligence Execution

Our solution spans the full data lifecycle: from collecting and cleansing over 35,000 addresses using Google Maps search and imagery, to delivering a polished, accessible application. It’s a true demonstration of full-stack location intelligence in action.

Impact-First Use of Google Maps Platform

We prioritized features that mattered most. With the Routes API, users could instantly navigate to verified sites. Real-time imagery from the Places API provided visual confirmation, building trust and removing friction—especially important in high-stakes public health scenarios.