Yep, there are. This question has been asked before:

Did Americans really give Native Americans smallpox blankets? with u/Reedstilt

How widespread were smallpox blankets? with u/tinrond

Smallpox Blankets; Were they actually distributed to Native Americans, how did the distributors pull this off without infecting themselves? with u/Gorrest-Fump

h/t to /u/mikedash whom I am shamelessly stealing the formatting for the above from.