DALLAS (NEXSTAR) — A new scientific report reveals cats develop a protective immune response to COVID-19, leading researchers to wonder whether it’s worth studying pets to aid in the development of a human vaccine.

“Resistance to reinfection holds promise that a vaccine strategy may protect cats and, by extension, humans,” researchers at the Colorado State University’s College of Veterinary Medicine and Biomedical Sciences wrote.

The report in the Proceedings of the National Academy of Sciences confirms cats and dogs can get the coronavirus but are unlikely to get sick. While scientists found cats can pass the virus to other cats, they discovered no proof that the animals can pass COVID-19 to humans, according to the New York Times.

At this point, it’s unclear why cats develop “neutralizing antibody titers” to COVID-19. Researcher Dr. Bosco-Lauth said cats appeared to show an immune response that was stronger than other animals. What’s also unknown is how long that immunity might last.

“This could prove a useful measurement for subsequent vaccine trials for both human and animal vaccine candidates,” researchers wrote.

The authors of the report say despite more than 1 million human deaths, there are only a handful of fatalities linked to COVID-19 with animals.

In the experimental work, researchers infected dogs and cats in a lab environment. They found cats would shed the virus and spread it to other cats while dogs did not. It’s worth noting that other studies have found dog-to-dog transmission.

To keep your cats safe from COVID-19, the researchers behind the paper suggest you keep cats indoors and observe social distancing with pets in the event a human in your household falls ill.