3 fully-vaccinated tigers at San Diego Zoo are suffering breakthrough COVID

Three tigers at the San Diego Zoo are feeling a little under the weather today. They have a mild case of COVID-19. All three tigers are fully vaccinated, as the zoo vaccinated hundreds of animals in its care this summer. These are the first COVID cases the zoo has reported since that vaccination drive. 

According to UC Davis zoological medicine professor Jenessa Gjeltema, certain species are more susceptible to infection. That may be the case for these tigers. 

“There's a variety of different factors that go into an individual host being infected. And that includes not only the receptor shapes, but also potential levels of exposure to the virus. So maybe an animal is in an environment where it's able to contact viral particles more easily or more particles than other animals,” she explains. “There can also be individual health factors that play a role as well that can make an animal more susceptible to infection, just like humans.” 



  • Jenessa Gjeltema - professor of zoological medicine at UC Davis, and head veterinarian at the Sacramento Zoo