I read The Great Influenza a few months ago after coming across it. I think I would have read it regardless of the current pandemic as I still believe my knowledge of the world in the WWI era to be lacking. The Great Influenza focuses on the Spanish Flu and its impact in the United States. It also details the history of medicine and virology, specifically as it pertains to the flu. The book is long and comprehensive but I really enjoyed it. It really went after the government’s role and response. That is to say, the response was eerily similar to COVID. Federal govt downplayed to minimize fear and prevent a panic, states formed wildly different response plans based upon who was in office, and the public was just as divided. Mask wearing was encouraged but many fought it as an infringement of their rights. It’s like we learned absolutely nothing, which is the scariest part of all.
It was during a discussion of this book at work that someone recommended The Pale Rider. This book is more about what happened around the world and the virus itself, how it mutated, where it may have started, and why it affected the 25-40 demo so much. The Pale Rider really got into the difference between disadvantaged groups and how the disease impacted them which is not usually discussed.
The Great Influenza really seems to support the idea that the pandemic began in Kansas, specifically 
an Army base that was training soldiers for WWI. The Pale Rider acknowledges Kansas as one possible origination point but adds three others: Spain, France, and China. The Spanish origin is the most debatable and probably least likely, though it does seem to be where many cases were first discovered, which is not inherently the same thing. Spinney also clearly addresses the issues with each theory. I really appreciated that she addressed that the Chinese Origin theory has roots in racism which cannot be discounted. Her book reads like a very comprehensive take on the global pandemic and is not just a history of the events but more of an anthropologic evaluation of the disease and its impact. Both books are very good and I recommend them if you are interested in the Spanish Flu, either from a U.S. perspective or global.