Gunther Eysenbach studies new methods of analyzing online information and communication patterns to track public health issues in real time. He analyzed over 3 million tweets about H1N1 influenza between 2009-2010 to study how the public discussed the pandemic on social media. Key findings included that discussion topics shifted over time and correlated with real-world events, and sentiment toward the H1N1 vaccine decreased then increased. Eysenbach argues that analyzing social media can provide timely insights into public concerns and experiences to inform public health responses during epidemics.