Posted on December 6, 2012
A long-awaited vaccine against a deadly zoonotic infectious disease in Australia became available Nov. 1.
The Equivac HeV vaccine protects against the transmission of the Hendra virus, which is endemic in native fruit bats in the warmer regions of the country.
Horses are thought to contract Hendra virus infection by ingesting feed or water contaminated by bats shedding the virus in their saliva, urine, aborted fetuses, or reproductive fluids.
The virus can also pass from animals to people and was first discovered in the Brisbane suburb of Hendra in 1994.
The Hendra virus horse vaccine project has received substantial funding from the Australian government over the years.
Most recently, in 2011, the Intergovernmental Hendra Virus Taskforce was formed, and the National Hendra Virus Research Program allocated funding to ensure that critical timelines for vaccine development were maintained.
Now, the Equivac HeV is available under permit from accredited veterinarians, following the Australian Pesticides and Veterinary Medicines Authority’s approval of a minor use permit earlier this year.
The Australian Veterinary Association has recommended that all horses be vaccinated against the Hendra virus, as the vaccine is expected to not only protect the health of horses but also reduce the risk of exposure for horse owners, handlers, and veterinarians. Hendra virus has claimed the lives of 81 horses on the continent, with nine deaths in 2012 alone, according to a Pfizer Animal Health press release.
Seven cases of transmission from horses to humans have also been reported. Of those incidents, five have involved equine veterinary personnel conducting postmortem or endoscopic examinations. In three cases of the seven, the infection was fatal.
A survey of equine veterinary practices in Queensland, Australia, showed that some veterinarians had given up equine work because of risks posed by Hendra virus.
Published in Emerging Infectious Diseases earlier this year, the study explored the issues faced by staff of equine veterinary practices relating to Hendra infection–control and workplace health and safety.
Researchers found that 12 of 20 veterinary professionals (60 percent) had dealt with one or more cases of suspected Hendra virus infection; seven of them (35 percent) had dealt with a confirmed case. Further, four of 18 veterinarians (22 percent) interviewed said they had stopped doing equine work, and 44 percent knew of one or more colleagues who had stopped doing equine work in the preceding year.
Concerns over personal safety and legal liability related to Hendra were given as the main reason for the decision to leave equine practice.
With no known cure for Hendra virus infection, the Equivac HeV vaccine is expected to be the most effective defense against the virus.
Rapid development of Equivac HeV was the result of an Australian-led international collaboration.
Pfizer Animal Health worked in partnership with Australia’s national science agency, the Commonwealth Scientific and Industrial Research Organisation, and its Australian Animal Health Laboratory.
Additionally, U.S. organizations, the Uniformed Services University of the Health Sciences, and the Henry M. Jackson Foundation for the Advancement of Military Medicine also contributed to the vaccine’s development.
Pfizer will oversee the training and accreditation of veterinarians working with the vaccine.