This recent post by University of Florida Extension offers a good overview of how vaccines work, the types of vaccines available and how to handle and administer them. It can serve as a training guide for new employees, be a refresher for pros, be sent as a follow-up to customers and used as an educational aid for new cattle owners. 4-Hers and FFAers working with calves will likely appreciate it, too.
Source: University of Florida Extension, June 17, 2022. Link. Vaccines expose the animal to parts of pathogens, challenging the immune system to react to a possible pathogen invasion by creating memory cells or antigens belong to that specific pathogen.