An orangutan named Karen, the first in the world to have open-heart surgery in 1994, has made medical history again: She’s among the first great apes to get a COVID-19 vaccine. 

In February, Karen, three other orangutans, and five bonobos at the San Diego Zoo have received two doses each of an experimental vaccine for animals developed by a veterinary pharmaceutical company, says Nadine Lamberski, chief conservation and wildlife health officer at the San Diego Zoo Wildlife Alliance.

“This isn’t the norm. In my career, I haven’t had access to an experimental vaccine this early in the process and haven’t had such an overwhelming desire to want to use one,” Lamberski says.

The milestone had been triggered by another: In January, a troop