It seems like it's been an eternity since the mad rush to get vaccinated in the United States. Some of us took desperate measures to skip ahead in line to get the first dose. Initially, the results were astounding -- in just approximately four months, 100 million Americans (~1/3rd of the population) had received their first dose. There was an unmistakable effect on the spread of COVID-19. Daily new cases dropped from a peak of roughly 250,000 in January to just 10,000 a day in July. Then, Something Happened What happened can best be illustrated using a chart (duh, this is Stats with Sasa). Just after it seemed we had gotten a handle on Coronavirus, it came back with a vengeance. Even though more Americans are fully vaccinated than ever, COVID is currently spreading twice as fast as last year's Second Wave. Although there were a few potential explanations, a clear one emerged: the virus had mutated. Enter the Delta Variant Originating in India, the Delta st...