Sloppy writing is my guess. Anti-venom, most likely. https://en.wikipedia.org/wiki/Snake_antivenom
Actually there is a rattlesnake venom vaccine for dogs.
Also there is some research looking into snake venom’s possible role against the CCP virus.
https://www.news-medical.net/news/20210114/A-snake-venom-enzyme-shows-anti-SARS-CoV-2-activity-in-vitro.aspx