A mystery virus
In September 1994, prominent Queensland horse trainer Vic Rail, his stable hand, and most of his horses fell ill to a sudden and mysterious illness. Within several days, Mr Rail and 14 horses were dead.
The (then) Queensland Department of Primary Industries (QDPI) collected specimens from affected race horses and submitted them for testing at CSIRO's Australian Animal Health Laboratory (AAHL) in Geelong, Victoria.
Since the first identified Hendra virus incident seven people have been confirmed to have been infected with Hendra virus, four of whom have died as a result of the disease.
Road to finding a vaccine
AAHL has been actively involved and has worked closely with QDPI and Queensland Health in each recorded Hendra virus incident since it first emerged in 1994.
In 1994 AAHL's diagnostic team isolated and identified what proved to be a new virus that had not been previously reported anywhere else in the world. Researchers initially named the virus equine morbillivirus, however, further genetic analysis showed that the most appropriate classification of the virus was to place it in a new genus within the family Paramyxoviridae.
It was later renamed Hendra virus, after the name of the Brisbane suburb in which the original outbreak occurred.
With the cause of the disease outbreak known, AAHL researchers developed diagnostic tests. At the time QDPI, Queensland Health and AAHL tested more than 2500 horse samples and 150 human samples, however, they did not find any new cases.
As a National Facility, AAHL provides diagnosis of emergency animal diseases, which includes:
- index case confirmation
- national emergency response capability
- use of accredited and validated tests.
The strength of AAHL's capabilities was clearly demonstrated by the manner in which the infectious agent was isolated, the disease reproduced in horses and the virus eventually identified using electron microscopy and gene sequence analysis, all completed within two weeks.
From 1994 - 2010, 14 clusters of Hendra virus infection were recorded in horses.
Then in 2011, Australia witnessed an unprecedented spike in the number of Hendra virus cases in horses in both Queensland and New South Wales with 18 outbreaks and 24 cases in horses reported. 2011 was also the year that the first dog tested positive to the Hendra virus. This unexpected transmission to a new species prompted an additional $6 million in Government funding towards Hendra virus research.
In July of the same year, the first confirmed outbreak of Hendra virus west of the Great Dividing Range was reported in Chinchilla, shattering perceptions that inland horse communities were safe from the virus.
The science community agreed that a vaccine specifically targeting horses was crucial to breaking the cycle of Hendra virus transmission from animals to people, as it would prevent the horse developing the disease and passing it on.
In May 2011 CSIRO announced the development of a prototype vaccine for horses which was an engineered soluble version of the G glycoprotein of Hendra virus (known as HeV-sG), previously developed in 2001 by Drs. Christopher Broder and Katharine Bossart, of the Uniformed Services University in Bethesda Maryland, USA. This vaccine was tested in several animal models in collaboration with the CSIRO as part of an extensive evaluation process where it was found to be potently protective against HeV infection.
Following rigorous safety testing, CSIRO along with its partners launched the Equivac HeV vaccine in November 2012. By March 2013 our scientists confirmed that horses were immune to a lethal exposure of the Hendra virus six months post vaccination.
The Equivac® HeV is a world-first commercial vaccine for a Bio-Safety Level-4 disease agent. This vaccine enables commercial and private equine activities to continue with minimal negative impact by increasing personal safety for horse owners, vets and others regularly interacting with horses. It also enhances security for the Australian horse industry and reduces time spent in quarantine.
The vaccine has reduced costs attributed to future disease response and containment and minimised the chances of the Hendra virus mutating and spreading more readily between horses, or from human-to-human.
The Australian Veterinary Association now recommends that all horses in Australia are vaccinated against the Hendra virus.
In August 2015 the Australian Pesticides and Veterinary Medicines Authority (APVMA) announced it has now fully registered the Hendra virus vaccine, Equivac® HeV, following a detailed assessment process, with the vaccine meeting every assessment criteria for registration.