According to Wikipedia, Richard Matheson’s horror novel I Am Legend –
was influential in the modern development of zombie and vampire literature and in popularizing the concept of a worldwide apocalypse due to disease. The novel was a success and was adapted into the films The Last Man on Earth (1964), The Omega Man (1971), and I Am Legend (2007). It was also an inspiration for George A. Romero’s Night of the Living Dead (1968).
First published in 1954, this is the cover of Bantam’s paperback edition from a decade later. It has surprisingly upbeat typography in multicolored all-caps Egyptienne, clashing with the cautionary wording. The darker illustration is by Sandy Kossin.
[More info on ISFDB]