Ian and Jennifer Glynn, The Life and Death of Smallpox. A fantastic biography of a nasty and still wily disease. It's the only infectious disease we've ever purposely eradicated, and that only happened by the skin of our teeth. We still aren't free and clear because of post-cold war fears of bad actors and weaponization. The history of the disease is particularly rich because the unmistakable symptoms make it easy to track in historical accounts across cultures. The story of vaccination is fascinating, and much less straightforward than I had always thought. It replaced the fairly ancient process of variolation - a home-brew inoculation using regular smallpox (rather than vaccinia or cowpox) that protected the individual but was still contagious and so was epidemiologically problematic. Just the stories about the choices people had to make about vaccinating/variolating their children were incredibly compelling. Do you expose your child to a known (though smaller) risk, or play the roulette wheel that they won't contract the severe disease? It makes our qualms about the side effects of modern vaccines seem almost petty.
The story of the virus itself is fascinating, as we can trace different evolutions of smallpox strains and related animal viruses, even in modern times. Did you know, that actually nobody knows where the strains we use for vaccines come from? The original was supposed to have come from the famous cow, but it doesn't appear to be related to any known cowpox. It may be the cow was infected with horsepox (now extinct, and so we can't check), or along the way the vaccine strain got contaminated with another pox virus.
I also thought this was really interesting because they do work on vaccinia and monkeypox at ASU - I had had no idea of the continuing usefulness of vaccinia to make vaccinations against other diseases! I read this book as part of a project I'm doing with a group in my Biology and Society class on infectious diseases in human history.