Discoveries at Frio Cave have raised concerns about the spread of rabies. Experts worry that the virus could potentially be transmitted through the air, highlighting the need for stricter safety measures. This discovery emphasizes the importance of handling the virus with extreme caution.

Searching for “Frio Cave” on Google makes the location in Uvalde County, Texas, appear to be a tourist haven. Tens of millions of Mexican free-tailed bats call the cave home, and it’s rapidly discovered that you can occasionally see the fluttering swarm spilling out of their dank, gloomy home right before sunset, clouding the sky in a “once-in-a-lifetime experience.”

But the history of Frio Cave is darker, and it isn’t mentioned on visitor websites. While spelunking there more than fifty years ago, two humans were rabies victims.

It’s hardly shocking that people could contract rabies from exploring a cave inhabited by bats. The horrifying illness, which is 99% deadly to people once signs like hyperactivity, hallucinations, seizures, and a phobia of water appear, is primarily spread by bats. One of the millions of bats could have bitten someone and spread a lyssavirus that causes rabies. But in this case, it doesn’t seem like the spelunkers were bitten. It appears that they contracted the virus directly from the air.

A group of scientists then looked into it. It was discovered that the rabies virus could spread, presumably through the air alone, to animals kept in vacant cages inside the cave. Additionally, the virus was isolated from samples that were gathered using methods for air condensation.

The program presented an unsettling idea. Had the most deadly virus known to man, rabies, become airborne?

It hadn’t, at least not in a way that would have led to extremely contagious human-to-human transmission. The cave became a “hot box” of infection because of the overwhelming number of bats that carried rabies. The majority of rabies cases are still caused by animal bites and scratches, and heat and sunshine quickly render the virus inactive. The public is currently only permitted to enter Frio Cave on guided excursions that stay close to the cave’s entrance, nevertheless, out of concern for their safety.

That does not preclude the possibility of rabies virus mutation leading to airborne transmission. It’s an RNA virus, and RNA viruses are known to mutate quickly. Researchers have discovered “a vast array of antigenic variants of this pathogen in a wide range of animal hosts and geographic locations.”

In addition, as two Italian researchers stated in a 2021 article, “Even single amino acid mutations in the proteins of Rabies virus can considerably alter its biological characteristics, for example increasing its pathogenicity and viral spread in humans, thus making the mutated virus a tangible menace for the entire mankind.”

Another way this could happen is through a “gain-of-function” experiment, where scientists use gene editing to modify the rabies virus to make it resistant to current vaccinations and give it the ability to travel through the air like influenza or measles. Recently, there has been heightened public scrutiny of gain-of-function research due to the remote possibility that the virus that causes COVID-19, SARS-CoV-2, was generated.

In a recent Substack post, Paul Offit—a pediatrics professor at the Children’s Hospital of Philadelphia and co-inventor of the rotavirus vaccine—discussed the possibility of enhancing rabies through gain-of-function.

“In the absence of an effective vaccine, it could eliminate humans from the face of the earth. The good news is that no one has tried to make the rabies virus more contagious. But that doesn’t mean that it’s not possible or that no one would be willing to try.”

Recently, GreatGameIndia reported that alarming statements from influential figures have raised public alarm about a possible bird flu pandemic. Media coverage exacerbates anxieties, while government mandates for testing and ambiguous responses from officials deepen public suspicion.