In addition to the many plays about AIDS:
Ibsen's Ghosts
Beirut, which was recently socially distanced performed and streamed, with Oscar Isaac and its original star, Marisa Tomei
The Plague, an adaptation of the Camus novel
While there have been few if any plays written during or in the aftermath of the 1918 flu, there was a play about it, Unity 18, which was well received