debtOr for the cheetah, getting vaccinated was no big deal: When a wildlife care specialist from the San Diego Zoo Safari Park called her, she walked up, sat down quietly and calmly, and received the shot.
“The animals are involved in the process and can walk away at any time,” explains Nadine Lambersky, wildlife health manager for the San Diego Zoo Wildlife Federation, who adds that the close relationships between San Diego’s wildlife specialists and the animals they care for make this gentle vaccination approach possible.
About 260 animals of various species have now received the experimental COVID-19 vaccine at the San Diego Zoo and Safari Park. Lamberski said most of the animals, like the cheetahs, “voluntarily” got the vaccine, but some were given it from afar by dart.
Although SARS-CoV-2 has caused disease in humans and resulted in millions of deaths, it has been discovered that multiple animal species can also be infected by the virus. This has led to the development and use of veterinary vaccines, primarily in zoos, but the question of which animal species need to be immunized now or in the future remains open.
Zoos house relatively small numbers of rare and valuable animals, and they clearly want to protect the ones they keep. To date, several animals have died in zoos due to COVID-19, including: Three snow leopards at the Children’s Zoo Nebraska and Two lions in an Indian zoo.
An added concern with the discovery that the virus has made its way into some wild animals is that SARS-CoV-2 could mutate in other species and reinfect humans, prolonging the pandemic – something that vaccination could potentially prevent and protect the animals themselves.
Development of animal vaccines
Human vaccines require expensive development programs and extensive testing, and are generally prioritized for humans. Animal vaccines generally undergo less testing and are often formulated differently. With the precedent of vaccines that can be used on multiple species, some veterinary pharmaceutical companies are aiming to develop COVID-19 vaccines that can be used on a variety of animal types.
As of August 2024, there are no fully licensed COVID vaccines for animals in Canada or the United States, although experimental vaccines have been approved for emergency use under certain circumstances. For example, in 2021, the US-based company Zoetis committed to donating approximately 26,000 doses of its COVID-19 vaccine for animals to zoos and animal sanctuaries in 13 countries, including the US and Canada. COVID-19 vaccines for use in animals are also being developed by federal agencies in Russia (Carnivac-Cov) and India (Ancovax). Additionally, Applied DNA Sciences and Evvivax have developed a vaccine, initially for cats, that is also being tested in mink.
Kevin Tyler, a microbiologist at the University of East Anglia, points out that the animal vaccines currently being used in Russia are inactivated virus vaccines, a more complex form of vaccine than recombinant or mRNA vaccines. This complexity means there is a greater risk of unexpected side effects, so such vaccines will require particularly rigorous testing before being considered for use in humans. But inactivated virus vaccines preserve more of the original virus’ proteins, or epitopes, so are likely to offer a broader range of protection, he notes.
Can animals get coronavirus?
Zoetis began developing the vaccine in February 2020, just as reports of vaccinating dogs were emerging. Positive reaction COVID-19 tests were conducted in Hong Kong and then conducted within the company. study The study involved 15 cats and 15 dogs. Results obtained before the first vaccine dose showed that the 20 animals that received the experimental vaccine developed a strong antibody response against SARS-CoV-2, while the 10 that received a placebo did not. No safety concerns were reported by the company. This is the only study of the vaccine published to date.
Less than 12 months after starting development, the company donated its first experimental vaccine to the San Diego Zoo, shortly after a group of eight gorillas died at the zoo’s Safari Park. Infected.
The vaccine is a subunit recombinant vaccine that uses a synthetic version of the SARS-CoV-2 spike protein and a proprietary adjuvant that Zoetis has used in its previous animal vaccines. It is administered in two doses, three weeks apart, and, unlike some drugs, does not require dosage adjustment based on the size or weight of the recipient animal.
“That’s the exact same amount you’d use for a 500-pound gorilla or a 5-pound mink,” said microbiologist Mahesh Kumar, senior vice president of global biologics research at Zoetis and the company’s leader in vaccine research and development.
The vaccine is stored at normal refrigerator temperatures and must be used within 24 hours after opening.
Experimental development of animal vaccines
Since the first donated vaccines arrived at the San Diego Zoo, the vaccine has been used to inoculate more than 100 animals at several zoos across the country, including the Oakland Zoo and the Philadelphia Zoo.
“It is unprecedented that one vaccine and one adjuvant has been used across more than 100 animal species without any major issues,” Kumar said.
Lamberski says she and her team administered the vaccine slowly to avoid any serious side effects to the animals. Following the gorilla outbreak, the zoo’s bonobos, gorillas, and orangutans were the first to receive the vaccine. The response from these animals was promising, so the team continued the vaccination effort, injecting a variety of species from pumas to otters.
“A few of the animals hadn’t eaten in a day and might have seemed a little less active,” she recalled. A few others appeared to be in mild pain.
Three tigers were vaccinated at the San Diego Zoo in October. suffered a sudden infection “I’d like to say it’s the vaccine, but I don’t know for sure,” Lamberski said.
As of August 2024, Zoetis’ vaccine is still considered experimental, but the company hopes to get USDA approval for use on mink. These small mammals are farmed for their fur and fat (fat is used to make oil for various products) and are particularly susceptible to COVID-19. Thousands of farmed mink around the world have died from the disease. There is also evidence of SARS-CoV-2 transmission from mink to humans. The majority of mink farms in the United States have committed to vaccinating their animals. Reports say.
What animal species can receive the COVID-19 animal vaccine?
When a veterinary vaccine becomes available, the question arises as to how many animals to vaccinate and why.
Zoos make their own decisions. Big cats and gorillas were the first to be vaccinated in the initial emergency rollout. Zoos may also vaccinate animals that have more contact with humans. Granby Zoo, for example, planned to vaccinate some of its Jamaican fruit bats that are part of an education program, but the majority of the zoo’s bats will not be vaccinated.
“The risks and stress associated with capturing an entire herd far outweigh the potential risks associated with contracting the virus in this particular situation,” she explains.
The tiger was one of many animals at the San Diego Zoo to receive the COVID-19 vaccine.
San Diego Zoo
The World Organisation for Animal Health (OIE) said there may be justification for vaccinating endangered species against COVID-19, but Keith Hamilton, head of the OIE’s Preparedness and Recovery department, said in a statement that there is no need to vaccinate pets at this stage because there is little evidence of pet-to-human transmission and therefore vaccinating animals “would not contribute to controlling the pandemic”.
Nikolaus Osterleider, a veterinary virologist at City University of Hong Kong, agreed: “There have certainly been cases of mink-to-human transmission, but so far human transmission has not been zoonotic.”
The problem is that this may change in the future.
“We are concerned that the virus is spreading well in urban monkey populations,” says Tyler, “and that the virus may mutate quite a bit and at some stage it could come back into the human population.” Urban monkeys come into very close contact with humans, including in many large cities in Asia and South America.
The possibility that animal species could serve as a reservoir for SARS-CoV-2, allowing the virus to reintroduce itself into human populations and prolong the pandemic, also worries Suresh Kuchipudi, a virologist at Pennsylvania State University. He and his team data A study of SARS-CoV-2 RNA prevalence in white-tailed deer in Iowa. PNASshowed that more than 30% of samples taken from 300 road-killed or hunted deer during the pandemic tested positive for SARS-CoV-2 RNA.
See “Researchers detect coronavirus in Iowa deer”
While there was no evidence of SARS-CoV-2 transmission from white-tailed deer to humans in 2021, they emphasized that further research is needed to better understand the spread of the disease among deer and the potential risk to humans. As of August 2024, several Reports It is suspected that deer can transmit the disease to humans, and while vaccinating wild deer would be “very challenging,” Kuchipudi said it could be an option in the future.
If a program to vaccinate wild and semi-wild animals, such as urban monkeys, against COVID-19 becomes a reality, Tyler suggested, it might rely on a yet-to-be-developed oral vaccine. Such a vaccine could be applied to the target animals’ preferred foods and distributed to places where the animals are likely to consume them.
For Kuchipudi, the real risk is missing potential populations of animals where SARS-CoV-2 could spread and mutate. Testing programs to monitor the spread of the virus in deer and other species might also be beneficial, he added. At the very least, not ascertaining which animals are at highest risk of contracting the virus and spreading it again to humans could leave us “blindsided” by future outbreaks.
“If we don’t address that as well, we may not be able to end this pandemic,” he said.
See “Tool identifies possible reservoir species for SARS-CoV-2”
FAQ
Can animals also get coronavirus?
- In addition to humans, multiple animal species can be infected with COVID-19. Infections have been recorded in pets such as dogs, cats, hamsters and ferrets, animals in zoos and sanctuaries such as big cats and non-human primates, domestic animals such as mink, and wild animals such as white-tailed deer and wild mink.
Is there an animal vaccine for SARS-CoV-2?
- In the United States and Canada, no animal vaccines have been fully approved for use against the new coronavirus, but experimental vaccines have been approved for conditional use in certain circumstances, including one made by Zoetis, which is being used to vaccinate large numbers of mammals in zoos, animal shelters and mink farms.
This article was published on December 9, 2021. It was updated on September 23, 2024. Dr. Deanna McNeill.
Correction (Dec. 9): This article originally stated that gorillas at the San Diego Zoo were infected with SARS-CoV-2. In fact, the infected gorillas were at the San Diego Zoo Safari Park. scientist I regret the mistake.
Clarification (Dec. 10): This article originally attributed a statement about whether pets should be vaccinated to an OIE spokesperson. At the OIE’s request, the statement has now been changed to Keith Hamilton, the organization’s head of preparedness and recovery.
