COVID-19 has now killed about as many Americans as the 1918-19 Spanish flu pandemic did — approximately 675,000.

The U.S. population a century ago was just one-third of what it is today, meaning the flu cut a much bigger, more lethal swath through the country. But the COVID-19 crisis is by any measure a colossal tragedy in its own right, especially given the incredible advances in scientific knowledge since then and the failure to take maximum advantage of the vaccines available this time.

"Big pockets of American society — and, worse, their leaders — have thrown this away," medical historian...