On March 9, ACS made the announcement to protect members, staff, and citizens of Philadelphia from the rapidly expanding trajectory of the novel coronavirus disease, or COVID-19, outbreak.

Philadelphia Governor Tom Wolf made a proclamation of disaster emergency on Friday, March 6, which led to the organization's decision to cancel the event. ACS CEO Thomas Connelly Jr., PhD, added that ACS could not ensure the safety of the over 15,000 expected attendees considering the new information.

Before making this decision, ACS gathered input from Philadelphia city officials, the U.S. Centers for Disease Control and Prevention, the World Health Organization, and ACS members and meeting attendees.