From the Document: "The trend in new daily U.S. cases of COVID-19 [coronavirus disease 2019] looked like it was improving during April and May and then took a sudden turn in what some started calling the 'second wave.' [...] New York's strong actions to stop the spread led to dramatic reductions in daily cases, and these reductions drove what appeared to be a downward national trend. Without New York included, the national trend in April and May was nearly flat, showing a crucial reduction in growth due to lockdown actions but little evidence of true success in defeating the virus. Community spread outside NY hovered remarkably close to 20,000 new cases per day for all of April and May. This helps explain why the re-opening of states under these circumstances has led to immediate exponential growth in cases. What we are seeing is not a 'second wave', but instead a 'continuation' of case increases across several U.S. states. Without the strong action taken in NY, the country as a whole would be seeing an even larger surge than what we are currently seeing. It is important for NY to remain vigilant as it continues through its various phases of reopening."
Lerner Center Data Slice No. 25
Syracuse University Lerner Center for Public Health Promotion
Lerner Center for Public Health Promotion: https://lernercenter.syr.edu/