Eighteen-year-old Okie is like many teenagers: He's filling out, he's a bit on the quiet side, and he has a predilection for sweet treats. And like many his age, a seasonal flu shot is highly recommended.
But as any doctor will find, the similarities end at the other end of the needle. Okie is a gorilla.
"They catch colds from us… we catch cold from them," said Shannon Finn, senior zookeeper of Zoo New England's Franklin Park Zoo. "They get miserable just like we do. They feel bad and tired and hot and not hungry... They get very miserable when they get sick."
Okie is not the only one who is getting a jab this season. Kambiri is a happy, active one-year-old -- but her young age makes her more vulnerable to viruses like the flu. To protect her, a trainer is giving Kambiri her first flu shot.
In total, eight of Zoo New England's gorillas will be getting a flu shot this year, a precaution that the zoo's assistant curator Jeannine Jackle said is as vital to the gorillas' health as it is to humans.
"They're very similar to us physically, so they can catch every disease that we can get," Jackle said. "With a one-year-old, like a human, we're more cautious. We want to get her vaccinated. Also with our 40-year-old, we worry about her too."
Jackle said a gorilla with the flu bears a striking resemblance to humans who are battling the bug, showing symptoms like a runny nose, sneezing, coughing and lethargy. If one gorilla gets the flu from another ape or a human, the virus can spread quickly to its primate companions.
So since 2005, Zoo New England has been vaccinating all of its gorillas against the flu, using vaccines donated by Children's Hospital Boston. Al Patterson, the director of pharmacy department for the hospital, said the vaccines they give to the zoo are identical to the ones a human would get.
"It's absolutely the same. We're using the human vaccine," Patterson said. "And it's not just the flu vaccine. We do a normal immunization series for baby apes and gorillas and primates," including shots for the measles, mumps and rubella.
The immune systems of gorillas and other great apes are actually quite similar to a human's, said Linda Lowenstine, professor of veterinary pathology at the University of California, Davis School of Veterinary Medicine. Previous studies have found virus-fighting antibodies for influenza A in gorillas, a form of the flu that humans catch too. But Lowenstine said scientists aren't sure if the primates are more or less susceptible to the flu than humans.
According to Lowenstine, there were some reports of apes dying in zoos during the flu pandemic of 1918 and 1919.
"Apes were dying in zoos with great frequency in those days because we didn't know how to properly care for them, so we don't know if they were dying from the flu or not," she added. "But now most zoos do choose to vaccinate for the flu."
Chasing a gorilla with a syringe of vaccine in hand may seem like a terrifying prospect, but Jackle said the process is pretty simple. Most apes in captivity are trained to present their body parts to trainers when given a special cue. Using this process, trainers can examine a cut, take a temperature, check a heartbeat or even give an ultrasound. This process of gorilla health care is an improvement over how things used to go, Jackle said.
"When I started at the zoo, we used anesthesia to treat a gorilla. We've tried to minimize that," Jackle said. "Now they can do it voluntarily."
To give an injection, a trainer gives a word or hand signal, and the gorilla will put its shoulder up to the mesh barrier. The trainer will show the gorilla the needle, perhaps giving the ape's shoulder a test touch with their finger or a stick. Then, after a quick stick with the needle, the newly vaccinated ape gets an apple or banana as a treat.
The process doesn't go smoothly every time.
"We do have one who's not particularly fond of doing it. So at that point, it becomes sort of a sneak attack," Jackle said.
To many people, this scenario may sound similar to the last time they took themselves or their children to the doctor for a flu shot. Jackle, who also volunteers at human flu clinics, said the two scenes match in more ways than one.
"It's very similar, especially in dealing with children. There's a lot of coaxing and bribing with lollipops," Jackle said.