The Hendra vaccine

Hendra banner - EVA

The Equivac® HeV vaccine became available to horse owners on 1 November 2012. It is an animal medicine, fully registered by the Australian Pesticides and Veterinary Medicines Authority (APVMA.) The vaccine has been declared as safe and effective (Source: Qld Parliament Report into the Hendra Vaccine; October 2016.) The vaccine was initially released to high-risk areas in Australia and then to all horse owners soon afterwards.

The vaccine was the result of scientific and collaborative efforts between the Uniformed Services University of the Health Sciences in Maryland USA, the Henry M Jackson for the Advancement of Military Medicine in Maryland USA, Pfizer Animal Health (now Zoetis), and CSIRO's Australian Animal Health Laboratory.

A timeline from 1994 to 2012 (the year the Hendra virus vaccine was released) has been developed to provide a summary of the research that has improved our knowledge of the deadly disease and contributed to the development of the vaccine. 

A review by Professor C Broder, Dr D Weir and Dr P Reid of the development of active and passive Hendra virus and Nipah virus animal vaccines has recently been published June 2016 in the internationally renowned journal Vaccine, available online here.

The current protocol for healthy microchipped horses over four months of age is two initial vaccinations administered three to six weeks apart, followed by a booster at six months, followed by annual boosters, with the AVA recommending that all vaccinations are recorded in a central database register. The vaccine should not be used in sick or immunocompromised animals. As no animal or human vaccines are regarded as 100% effective in all individuals, appropriate PPE, good personal hygiene and biosecurity practices should always be used when dealing with sick, vaccinated or unvaccinated horses.

The vaccine is only available to veterinarians through the manufacturer. The reasoning behind this is based on the fact that because Hendra is such a lethal disease, the vaccine needs therefore to be handled, stored and administered by veterinary professionals, to ensure adherence to correct administration protocols in order to protect animal and human health, in line with the best international standards for preventive medical care. In addition, the record of horse vaccination is entered into a central database which can be used by veterinarians, event organisers, horse owners and government agencies to check the horse's current vaccination status.

No vaccinated horses have ever contracted Hendra virus, whilst 21 laboratory confirmed HeV infections in horses have occurred in Queensland and NSW since vaccine release in November 2012.

The vaccine is the most effective way of reducing the risk of Hendra virus infection and disease and provides a workplace health and safety, as well as a public health benefit. There is a high level of confidence in the efficacy and safety of the vaccine held by veterinarians and by both Queensland and NSW State Governments and the Australian Government through the Animal Health Committee. This has been evidenced in outbreak situations since the vaccine became available. Fully vaccinated horses in contact with infected animals are now regarded as “low interest” horses by government agencies handling outbreak situations, and are managed as such by early release from quarantine following approved external decontamination processes.

From 2013-2015 there were seven horse deaths in NSW. Of the seven NSW properties affected there were 19 horses in contact with the HeV positive cases which had not been vaccinated. These 19 in contact with horses were then vaccinated and subsequently did not become infected. In an outbreak in Queensland on the Atherton Tablelands in July 2015 where one horse died from HeV, there were also six vaccinated horses and three unvaccinated horses on a property. These six vaccinated horses were regarded by QDAF’s Biosecurity Queensland as “low interest” horses and subsequently released early from quarantine in line with national Animal Health Committee policy.