It turns out that humans aren’t the only species on this planet at risk for COVID-19. Certain species of animals have also been infected by the novel coronavirus, which causes the disease, so the medical staff at Brookfield Zoo is taking action by vaccinating at-risk animals in the collection.
Over the past week or so, veterinarians and support staff have begun giving COVID-19 inoculations manufactured by a company called Zoetis, which produces other vaccines for domestic animals.
Dr. Mike Adkesson, vice president of clinical medicine for the Chicago Zoological Society, which operates Brookfield Zoo, said the team of five vets, 10 support staff and 50 to 100 animal care staff have been preparing animals for their shots and then administering them in a systematic fashion.
“It’s been a huge team effort to get to this point,” Adkesson told the Landmark in a phone interview.
When the vaccine effort is complete, said Adkesson, some 300 animals will have been vaccinated. Like the Pfizer and Moderna vaccines for humans, the animals will receive two doses of the vaccine, three weeks apart, which means this effort will take some time to complete.

On Sept. 7, for example, the staff administered doses to 17 animals, and those are some of the easier species to vaccinate.
“A lot of the bigger primates are trained for injection behavior,” said Adkesson, adding that gorillas, for example, will present their arms by walking up to the habitat’s outer mesh to be inoculated and some smaller primates are crate trained. It’s also relatively easy to vaccinate small mammals that can be handled more easily.
“The best case situations are where they are fully cooperative,” Adkesson said. “These animals have trusting relationships with their care teams.”
While there have been no COVID-19 cases among animals at Brookfield Zoo, Adkesson said, cases have popped up at other zoos among certain species. Among those susceptible are larger primates, big cats such as lions and tigers, bears and small carnivores like otters and minks.
Also among those animals first in line to receive vaccines are Brookfield Zoo’s “animal ambassadors,” which come into direct contact with zoo visitors both onsite and at offsite events.
COVID-19 symptoms in animals are similar to those experienced by humans, upper respiratory issues including coughing and sneezing. Veterinarians are still learning how COVID-19 is spread in animal populations, whether that’s animal-animal or human-animal transmission.
“We know it’s not spreading wildly,” said Adkesson.
Because of the uncertainty, said Adkesson, Brookfield Zoo early on masked up the medical staff and tried to maintain physical distance from animals. When zoo collections include endangered species, like Amur leopards – where there are less than 200 left in the world – it’s imperative to protect them from preventable diseases like COVID-19.
“We immediately put precautions in place,” Adkesson said. “We’ve been very cautious with this. It’s hard because staff have strong, tight relationships with the animals.”
Zoetis is providing the vaccines to zoos and aquariums (some of which have animal ambassadors that are small mammals, said Adkesson) at no cost. Two weeks after an animal’s second vaccine, it is considered fully protected against COVID-19.
Getting animals like big primates and the zoo’s Rodrigues fruit bats inoculated will also mean that the Tropic World: Africa and Australia House exhibits, which have been closed to the public since March 2020, can reopen their doors.
As we gained knowledge about COVID-19, we strategically opened our buildings back up,” said Adkesson. “But with exhibits like Tropic World: Africa and Australia House, where the bats fly freely, we didn’t feel like we could maintain enough distance between those areas and people.”