The story of America’s rabid raccoons begins in Florida. Rabies was once rarely found in raccoons, but in the ’50s, an outbreak began spreading from the Sunshine State. It diffused first to neighboring states and then made a great leap north into the mid-Atlantic, possibly via the shipment of over 3,500 Florida raccoons to hunting preserves in Virginia. From there, rabid raccoons ambled their way as far north as Canada and as far west as Ohio. The East Coast became “one solid belt of raccoon rabies,” says Charles Rupprecht, the former chief of the CDC’s rabies program.
In the early days of the outbreak, officials quickly realized that mass killings of raccoons would not be popular with the public. Residents on one Florida island with a rabies outbreak were so attached to their raccoons that a restaurant owner was feeding them 400 pounds of dog food a month.
For the past 30 years, the U.S. government has embarked on a far more unusual and elaborate campaign: mass immunization of raccoons. Every summer and fall, the USDA, in collaboration with local agencies, drops millions of packets of oral rabies vaccines over the U.S. by air and by hand. The vaccines come in two flavors: fish meal and vanilla. When a hungry raccoon bites into the packet, the liquid vaccine coats its mouth, immunizing it against the rabies virus. We’re now trying to save raccoons from the rabies outbreak we once unwittingly helped unleash. As far as management strategies for dangerous wildlife go, mass immunization is a pretty gentle one.
Distributing the vaccine is a three-pronged process. Small airplanes equipped with a conveyer belt—“a little bait treadmill,” Kirby says—drop the vaccines over large, empty rural expanses. Helicopters that can fly lower drop them over suburbs. Dense urban areas are the hardest to reach: The team actually walks around setting up bait stations or J-shaped tubes filled with the fish-meal polymer cubes. The idea is to make sure that raccoons, specifically, try to eat these; they can reach into the pipes with their dexterous hands, whereas possums, skunks, and feral cats cannot. The program is aiming to vaccinate at least 60 percent of raccoons in an area to stop the spread.