BIAH’s Commitment to Eliminate Rabies in the U.S.

Louis Pasteur died on September 28, 1895, and in 2007, the date was named World Rabies Day to honor his work in creating the first rabies vaccine, which in turn laid the foundation of rabies prevention. While human rabies cases in the U.S. are quite rare, worldwide, rabies kills a person every nine minutes.¹  The disease is especially prevalent in parts of Africa and Asia, but is also found in wildlife populations in the U.S., in species such as raccoons, skunks, and gray foxes.

An innovative delivery system for an oral rabies vaccine can help in the fight to prevent a disease that kills thousands of people around the world each year. It’s an effort that intertwines the pioneering work of Louis Pasteur, wildlife infectious disease researchers, and Boehringer Ingelheim Animal Health, along with local, state and federal governments, universities, and pilots.

Yes, pilots. The effort to control rabies in U.S. wildlife populations has taken to the skies. Each year, beginning in August and running through September, a federal initiative is undertaken to control raccoon-spread rabies in the eastern part of the country, from Maine to Alabama. The National Rabies Management Program run by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service Wildlife Services (USDA-APHIS-WS) distributes an oral rabies vaccine — RABORAL V-RG® manufactured by Boehringer Ingelheim in Athens, Ga. — primarily via drops from airplanes. It is the largest coordinated effort to control rabies in the U.S.

“The one thing about viruses is that if you let your guard down and you stop looking for them and you start thinking the virus is gone, they always come back,” says Dr. Joanne Maki, Technical Director of the North America Veterinary Public Health group at Boehringer Ingelheim Animal Health (BIAH).

Rabies and Raccoons

Raccoon-spread rabies in the eastern U.S. got an accidental boost in 1977, when hundreds of rabid raccoons were trapped in Florida and shipped to private hunting clubs in Virginia.² It created a snowball effect that is still being felt decades later.

“Those infected raccoons caused a large outbreak that went from the mid-Atlantic states all the way up into the Northeast and into Canada,” says Dr. Maki. “It created a public health emergency in the eastern U.S. The Centers for Disease Control and the federal government got involved, and now, 30 years later, we still have this threat.”

Today, wild animals account for nearly 93% of reported rabies cases in the U.S. “In the eastern United States, the majority of the time, the originating species for wildlife rabies outbreaks is the raccoon,” Dr. Maki says. “In the Midwest, it is primarily the skunk. In the Southwest, it is the skunk and the gray fox. Across the United States, we all have bats.”

The “One Herd” Immunity Approach

Each year, APHIS manages a team that flies over rural areas of more than a dozen U.S. states. Roughly 85% of the vaccines are distributed using fixed-wing airplanes; the remainder are dropped by helicopters or from vehicles on the ground. The program requires a massive amount of planning, from plotting GPS coordinates to calculating the population density of raccoons in targeted locations.

“They distribute from sunrise to sunset,” says Dr. Maki. “They place approximately 5 to 7 million doses of the product all the way from Maine and throughout New England, New York, Pennsylvania, West Virginia, the western part of the Carolinas, and as far south as Birmingham, Alabama.”

The strategy is to create vaccination zones where rabies is geographically eliminated in order to minimize the impact of raccoon rabies in the eastern United States and to keep it from spreading to other areas of the country. “The goal is to create a barrier of vaccinated raccoons to prevent the spread of rabid raccoons westward into the rest of the United States,” Dr. Maki says. “If you can vaccinate a minimum of 50% of a reservoir species such as raccoon, you will interrupt the transmission of the virus between animals in that population. You would establish a herd immunity in a geographically defined area.”

How RABORAL V-RG® Works

Small waterproof bags of RABORAL V-RG® are hidden in wax-covered sachets — like the catsup packets you get from a fast-food restaurant — covered in a stinky fishmeal coating. It is a smell that is irresistible to raccoons and other wildlife such as gray foxes, skunks and coyotes.

When a raccoon bites through the bait, it punctures the packet and gets a liquid rabies vaccine in its mouth. “The liquid dose actually goes into the oral cavity and is taken up by the tonsils and initiates an immune response in the tonsils,” Dr. Maki says. “After several days, it becomes a systemic immune response.”

The baited packets contain a recombinant vaccine that cannot cause rabies. “The vaccine is a poxvirus that only contains one additional gene, the rabies glycoprotein” says Dr. Maki. “When the virus goes into the tonsils and expresses this one protein, it kicks off the immune response. Within 3 or 4 weeks, you can find circulating antibodies against rabies in the animal’s blood. That animal is vaccinated just like a dog or cat.”

Why It Matters

Veterinarians administer routine rabies vaccinations because they are required to, says Dr. Maki, and it can seem a mundane part of their clinical practice. “But if they want to understand more about how rabies can impact people, just look outside our borders. September 28th is World Rabies Day and there are still 60,000 people estimated each year dying of rabies. Often, it is children who are being bitten by unvaccinated dogs in rural areas — it is a disease of poverty and lack of public health infrastructure. My job has allowed me to realize how great we have it in the U.S. It is not just a vaccine issue; it is truly a public health issue.”

The One Health aspect of rabies vaccinations is a critical one. “Not only are we as veterinarians having to look at multiple species but because of our training in food production and food safety, and our ability to ensure that we have quality handling of livestock that are in the food chain, we learn about diseases that can be transmitted to humans,” says Dr. Maki. “One of our criteria for getting out of vet school is to know how to stop the transmission of these infectious agents to people.”

If there is a silver lining to the current Covid-19 pandemic, says Dr. Maki, it is that “prior to Covid, I don’t think many people gave public health much thought. Public health is central to our quality of life and diseases will always be there. We have got to do our part to prevent the spread.”

Boehringer Ingelheim’s Commitment

Boehringer Ingelheim Animal Health’s long-range vision on how to deal with animal diseases is to find cost-effective and humane ways to prevent disease. BIAH’s support of the National Rabies Management Program reflects that mission. “It’s a quiet program. Not a lot of people know about it. It’s not real flashy. But it’s providing a public health service,” Dr. Maki says. “The goal is to prevent human exposure to rabies. It’s not just providing the vaccine. It’s to prevent the disease at every level. That’s the passion behind Boehringer Ingelheim.”