A Bite-Sized Breakthrough: Can Oral Rabies Vaccines Finally Eliminate Dog-Mediated Rabies?

Rabies remains one of the deadliest infectious diseases on the planet—and one of the most preventable. Despite decades of progress controlling rabies in wildlife, nearly all human rabies deaths today are still caused by dogs. Now, a new generation of oral rabies vaccines may offer a practical way to close that gap and finally drive dog-mediated rabies to zero.

A recent study published in PLOS Neglected Tropical Diseases evaluates the safety and potential impact of SPBN GASGAS, a third-generation oral rabies vaccine developed specifically for dogs. Unlike traditional injectable vaccines, SPBN GASGAS can be delivered in an edible bait, allowing dogs—especially free-roaming and street dogs—to vaccinate themselves.

Why Dogs Are the Missing Link

Oral rabies vaccination has been a public health success story in wildlife. Across Europe and North America, bait-delivered vaccines have helped eliminate rabies in foxes and raccoons. Yet globally, 99% of human rabies deaths are linked to dogs, not wildlife. These deaths occur primarily in Africa and Asia, where tens of thousands of people—40% of them children under 15—die from rabies each year.

The challenge has never been vaccine effectiveness, but access. Free-roaming dogs are difficult to catch, restrain, and inject. As a result, vaccination campaigns often fail to reach the critical 70% coverage needed to interrupt rabies transmission.

A Vaccine Designed for the Real World

SPBN GASGAS, developed by Ceva Santé Animale, is a genetically engineered descendant of the long-used SAD B19 rabies vaccine strain. It has been modified to eliminate the risk of causing disease while retaining strong, long-lasting immunity.

In the newly published safety assessment, researchers—including Dr. Gowri Yale, Global Rabies Programme Director at Ceva—compiled more than 30 years of laboratory, regulatory, and field data. Their conclusion: the vaccine poses no safety concerns to humans, even in the event of contact with leaking baits or recently vaccinated dogs.

Extensive testing across dogs and multiple non-target species—including cats, skunks, foxes, mongooses, and swine—revealed no serious adverse effects, even with overdosing, repeated doses, or alternative routes of exposure. The vaccine was not shed beyond the entry site and was not transmitted from vaccinated pregnant animals to their offspring.

Addressing Safety Concerns Head-On

Because live vaccines can theoretically revert to virulence, researchers subjected SPBN GASGAS to repeated laboratory passaging and whole-genome sequencing. Across multiple tests, the vaccine’s critical genetic modifications remained stable, with no evidence of reversion—even when administered to highly susceptible animal models.

To assess potential risk to immunocompromised people, the team also tested the vaccine in immunocompromised mouse models. The vaccine was safe when given orally or subcutaneously and only caused disease when injected directly into the brain—an exposure route that does not reflect real-world use.

The Path to Elimination

According to Yale, oral rabies vaccines could dramatically increase vaccination coverage by eliminating the need to chase, restrain, or inject dogs. Field teams can be trained in just days, and vaccination campaigns can be carried out by small groups—sometimes as few as two people on a motorbike.

While oral vaccines are more expensive per dose than injectable vaccines, their overall cost-effectiveness is higher. Injectable campaigns require large teams, vehicles, and skilled personnel, while oral vaccination reduces logistical barriers and operational costs.

The researchers emphasize that how baits are deployed matters. A “hand-out and retrieve” approach—where trained teams directly offer baits to dogs and collect any leftovers—is considered the lowest-risk strategy for human exposure.

A Realistic Endgame for Rabies

With wildlife rabies already eliminated in many regions using oral vaccination, experts believe the same strategy could work for dogs—if implemented at scale alongside existing tools.

“If oral rabies vaccines are rolled out alongside current control efforts, the problem is solved,” Yale notes. “Rabies is removed at its source.”

For veterinarians, public health professionals, and global health advocates, SPBN GASGAS represents more than a new vaccine—it represents a realistic final step toward eliminating one of the world’s oldest and deadliest zoonotic diseases.