Laxmi Bachanalaya
Legally available public-domain books and openly licensed reading materials.
Edward Jenner
Various
J. Z. Holwell
Thomas Dimsdale
Marylebone Anti-Compulsory Vaccination League
Sir Gilbert Blane
T. M. Greenhow
Daniel Sutton
These books are free to read. Each is in the public domain in the United States; check your own country's rules before you copy or share one.