Herd immunity describes the synergistic property of immunity. Doubling the percentage of individuals that are immune to a disease provides more return on reducing the overall spread of disease. Likewise, a single individual at risk places the individuals around them at risk as well, regardless of their immunity.
We map a proxy for epidemic vulnerability by scraping twitter for propensity of anti-vaccine tweets, categorized by machine learning. These tweets range from pre-scraped past tweets to real-time streaming tweets. Flight data is scraped to find points of connectivity that can be simulated.