Hendra virus

In this article

  1. Background
  2. Research findings
  3. Continuing research
  4. Biocontainment

Continuing research

Page 3 of 4

CSIRO maintains a significant program of research on bat-borne viruses, including Hendra virus research, with 25 scientists working in this critical area.

These virologists and veterinary pathologists are supported by a large group of engineers, technicians and other support staff who operate and maintain AAHL's highly specialised maximum biosecurity laboratory.

Since 2005 there have been a number of major research breakthroughs which have improved our knowledge of Hendra virus.

The first breakthrough involved an international team, including AAHL researchers, who identified the part of the cell membrane to which both Hendra and Nipah virus attach in order to enter and infect the cell.  This discovery accelerated research in many different areas, including the development of improved diagnosis, vaccine, and anti-viral drug candidates.Electron micrograph of Hendra virus.

The group at AAHL in collaboration with US scientists then evaluated a potential human vaccine to provide protection against both Nipah and Hendra virus. The results of this research, published in July 2005, represented significant progress towards the development of a human vaccine to be used in the event of another natural outbreak, a laboratory accident, or deliberate misuse.

The second major breakthrough occurred in 2008 when an international research team, including AAHL scientists, evaluated a recombinant subunit vaccine formulation to protect a small animal model against the lethal Nipah virus. This paper was published in the journal Vaccine in July 2008[1]. This research provided significant progress towards the development of a prototype Hendra virus vaccine for horses.

In 2009 a scientific team from CSIRO and the US demonstrated that administering human monoclonal antibodies after exposure to Nipah virus protected animals from serious disease in an infection model.

This research breakthrough in the fight against Henipaviruses shows great potential to save the lives of people who become infected with the virus.

The results of this latest research were published in the open access journal PLoS Pathogens in October 2009[2]. The research was conducted in collaboration with scientists from the Uniformed Services University of the Health Sciences, National Cancer Institute and the National Institutes of Health in the US.

Scientists at AAHL are also studying bat ecology and the bat immune system to determine how viruses, such as Hendra virus, maintain themselves in bats and how they 'spill over' into humans and other animals.Image of two horses.

Research to understand more about zoonotic diseases is also being undertaken, with a focus on the interaction of bats and viruses and identifying and characterising new and emerging infectious agents.

Hendra virus horse vaccine

In May 2011, CSIRO announced that a prototype Hendra virus vaccine for horses successfully prevented infection with the virus. This is important as it could break the cycle of the virus transmission from flying foxes to horses and then to humans – preventing the horse from developing the disease as well as passing it on to people.

To date, the infection pathway of humans with Hendra virus has been from bats to horses, then from horses to humans. There is no evidence of human to human transmission or of direct bat to human transmission.

Given this scenario, CSIRO believes the best opportunity for intervention in the human infection pathway is to vaccinate horses to prevent the disease in horses and reduce virus shedding; both of these are critical to reduce the risk of spread of the virus to people.

The development of the vaccine was the result of a close collaboration with Dr Christopher Broder of the Uniformed Services University of the Health Sciences (the US federal health sciences university) supported by the US National Institutes of Health and Pfizer Animal Health Australia. The high containment facility at AAHL was essential for evaluating its beneficial effects as it is the only laboratory in the world where this work could have been undertaken.

Following a surge in Hendra virus cases in 2011, regulatory authorities agreed to assess the Hendra virus horse vaccine with high priority during its registration process. The Intergovernmental Hendra Virus Taskforce was formed, and the National Hendra Virus Research Program allocated funding to ensure critical timelines for vaccine development were maintained.

In 2012, the Australian Pesticides and Veterinary Medicines Authority granted the Hendra virus horse vaccine (Equivac HeV) a Minor Use Permit after the vaccine met all essential safety, quality and efficacy requirements.

Later that year, Pfizer Animal Health made the Equivac HeV vaccine available, under permit, for accredited veterinarians to administer to horses, and offered vets the opportunity to attain their Equivac HeV vaccine accreditation online via Vets Australia [external link].

References

1. McEacherna JA, Bingham J, Crameri G, Green DJ, Hancock TJ, Middleton D, Feng Y-R, Broder CC, Wang L-F, Bossart KN. 2008. A recombinant subunit vaccine formulation protects against lethal Nipah virus challenge in cats [external link]. Vaccine. 26(31): 3842-52.

2. Bossart KN, Zhu Z, Middleton D, Klippel J, Crameri G, Bingham J, McEachern JA, Green D, Hancock TJ, Chan Y-P, Hickey AC, Dimitrov DS, Wang L-F, Broder CC. 2009. A neutralizing Human Monoclonal Antibody Protects against Lethal Disease in a New Ferret Model of Acute Nipah Virus Infection [external link]. PLoS Pathog 5(10): e1000642. doi:10.1371/journal.ppat.1000642.