Q&A: Getting the facts right on deadly hendra virus

A horse is vaccinated against the Hendra virus.
A horse is vaccinated against the Hendra virus. Claudia Baxter

THOUSANDS of Australian horse owners have been urged to give their horses critical follow-up vaccinations against the deadly Hendra virus, which can pass from horses to humans.
Since launching in late 2012, more than 80,000 Australian horses have been vaccinated with Equivac HeV, the most effective way to help protect them against the deadly virus, which remains a threat across the country.


What is the Hendra Virus?

Hendra virus (HeV) causes a potentially deadly viral disease that can be spread

from horses to humans.

There are no proven treatments for Hendra virus.

Hendra virus has only ever been reported in Australia.

It was first detected in Brisbane in 1994, and infections have been reported as far north as Kuranda and as far south as Kempsey.

In 2013 there were four outbreaks reported in New South Wales and four outbreaks within Queensland.

Where does the Hendra virus come from?

Fruit bats (flying foxes) are the natural hosts of the Hendra virus.

How is Hendra virus infection spread?

It is thought that the Hendra virus is transmitted from fruit bat to horse via contamination of food or water with fruit bat urine, faeces or body fluids.

Hendra virus can be spread from horse to horse and horse to human through close contact with respiratory secretions and/or blood from an infected horse.



Can Hendra virus be prevented?

Equivac HeV aids in the prevention of Hendra virus infection in horses from four months of age.

Equivac HeV is a 'subunit' vaccine, meaning it contains only a small part of the Hendra virus; a protein from the virus surface.

How does Equivac HeV work?

The vaccine stimulates the production of protective antibodies.

If the horse is subsequently exposed to Hendra virus, the antibodies will bind to the viral particles preventing them from establishing an active infection in the horse.

The viral particles bound to the antibody are then further processed by the immune system and eliminated.

How is the vaccine administered?

Approved veterinarians can administer the vaccine by injection into the muscles on

the side of the neck.

Two 1mL doses are given 3 - 6 weeks apart, and antibodies are generated within three weeks of the second vaccine dose being given.

How effective is the vaccine?

Trials have shown complete protection when vaccinated horses were exposed to

an otherwise lethal dose of the Hendra virus.

Can Equivac HeV cause Hendra virus infection?

No, the vaccine is not live and cannot cause infection in horses.

Live virus is not used at any stage in manufacturing this vaccine.

Where can horse owners go for more information?

Horse owners should speak to their vet for more information about Equivac HeV or visit




Why do horses need a booster every six months?

If horses miss the 6-month booster vaccine, they could be at risk of contracting Hendra virus.

Current studies support a duration of immunity of six months, meaning failure to administer a 6-month booster can leave horses potentially vulnerable to Hendra virus infection.

If there have been no cases of Hendra in my region, should I still vaccinate my horse?

Yes, horses are at potential risk of Hendra virus in any location visited by flying foxes.

That is a huge expanse of Australia and over the last few year's outbreaks have occurred in parts of Queensland and New South Wales.

Topics:  flying foxes hendra livestock vaccination