Anti-Vaxxers Are Targeting a Vaccine for a Virus Deadlier Than Ebola
Cedars Ernest was a certifiable goofball. He was a purebred Shire, a type of British draft horse that once specialized in hauling carts of ale. Nicknamed Ernie, he tipped the scales at more than a ton, and had a chocolate-brown coat with luxuriant white hair feathering his hooves. His owner, Nicole Carloss, a horse trainer in Queensland, Australia, adopted him in 2013, when he was 7 years old, and he immediately found his place in her family.
“He would burst open the screen door and try to do the dishes with you,” Carloss said. When her children played in their sandbox, Ernie would plop his front hooves down next to them. Carloss took Ernie to compete in shows throughout the state, where he would strut around with a sequined browband. “He stole everybody’s heart,” she said.
In August 2016, Carloss came home from work and headed out to the fenced pasture to visit Ernie. He lifted his head dolefully, like Eeyore from Winnie-the-Pooh. His eyes were empty, his breathing was strange, and he wobbled when he walked. Carloss suspected he might have been bitten by a snake, but she saw no fang marks on his legs.
She called a local veterinarian and described Ernie’s symptoms. The vet asked Carloss if her horse had been vaccinated for Hendra.
“No,” she replied.
Carloss had anticipated the question, but that didn’t make it any less unsettling. Hendra is a deadly virus that is endemic in Australia and is spread by bats. Since the first documented outbreak in horses in 1994, Hendra has killed 102 of the animals. It kills people, too: On seven occasions, it has crossed from sick horses to the veterinarians and other professionals attending them, leading to four excruciating deaths. For the last six years, the animal-pharmaceutical company Zoetis—previously a Pfizer subsidiary—has sold a vaccine called Equivac to prevent horses from contracting the virus.
A lot of horse owners, however, don’t vaccinate against Hendra, citing its expense, the rarity of the disease, or anecdotal reports of severe side effects. According to a survey published last year in the journal PLOS One, approximately 43 percent of horse owners in Queensland haven’t vaccinated their horses. In some inland parts of the state, that number is as high as 70 percent.
“I don’t believe in injecting chemicals into horses, especially if it’s not tested,” Carloss said, referring to the fact that regulators, citing the danger posed by an outbreak, initially allowed the vaccine to be sold under a provisional license. “More people get hit by cars or shark attacks.”
Many vets see the situation to don protective masks and clothing, and the amount of care they can provide is limited until Hendra can be ruled out with a test—a process that typically takes a day or more. The vaccine has divided the horse community, pitting owners against vets and revealing that science alone is not enough to prevent the next global pandemic. “People are very complex,” says Raina Plowright, a disease ecologist at Montana State University who studies Hendra. “You can’t roll out a vaccine and think everything will be okay.”
