Animals, vaccines, and COVID-19.

Animals, especially mammals, have played a critical role in the COVID-19 pandemic. The COVID-19 virus originated in animals, and the virus can jump back and forth between humans and animals. Moreover, animals have been central to the development of the various vaccines against the virus now employed around the world, continuing a long history. The interrelationships between animals and humans in both disease transmission and its prevention call for an interdisciplinary approach to medicine.