In November 2020, millions of mums raised in captivity for the European fur industry were slaughtered when the new coronavirus was detected among them. The alert prompted American veterinary drug manufacturers to start researching animal vaccines, but a group of scientists had already developed one and inoculated it with a relative of the mink on the brink of extinction: black-legged weasels.
Animals housed at the National Center for the Conservation of Black-footed Ferrets (NBFCC) in Colorado (USA) were vaccinated. Even though the country has not detected a single case on mink farms, the discovery of the virus in a wild mink in Utah sparked the warning among conservationists.
In mid-March, 18 ferrets (all male and one year old) received the first dose of the vaccine; the second booster dose was administered a few weeks later. Scientists waited a month to test the animals’ blood, celebrating the discovery of antibodies.
The vaccination program expanded in mid-September, when 120 of the 180 ferrets housed in the center received the dose (the remaining 60 animals were not immunized as a precaution, since the lifespan of this species is 4 to 6 years in captivity) .
According to microbiologist Tonie Rocke, a researcher at the National Wildlife Health Center, “so far, the vaccine seems safe, but there is still no data to show whether it really protects animals against the disease. We have no idea if this is really going to work. ”
The biggest problem, she says, is in the animals themselves. In addition to being a species close to the mink, they are genetically very similar, since they descend from a small group that started to breed in captivity, which weakens their immune system: if one is vulnerable, it is almost certain that everyone will be.
“We have no direct evidence that black-footed ferrets are susceptible to covid-19, but we would not like to find out,” said the researcher, who started working on the vaccine in mid-March.
In 1979, the species was declared extinct, until a small population hidden near a farm in Wyoming helped the lineage to recover: these 18 animals started a captive breeding program.