Timeline: Tracking the Spread of Swine Flu

A summary of the major developments in the H1N1 outbreak.

ByABC News
April 30, 2009, 9:33 AM

June 11, 2009— -- Below is a timeline of the events in the rapidly changing flu outbreak. For answers to frequently asked questions and information on the latest developments, visit ABC News' On Call Swine Flu Center.