New variant of RHDV1 K5 for improved rabbit biocontrol

A new variant of rabbit haemorrhagic disease known as RHDV1 K5 has been approved for registration in Australia by the Australian Pesticides and Veterinary Medicines Authority (APMVA). The Australian release of RHDV1 K5 is planned between March and June 2017.

RHDV1 K5 is a potentially significant biological control tool for pest rabbits in New Zealand. While exact figures are unknown, it is expected that there will be improved “knockdown” (deaths) in areas where the current strain of RHDV is less effective.


Is this strain new? Where did it come from?
RHDV1 K5 is a new strain but not a new virus. It is a Korean strain of the existing RHDV1 virus that is already widespread in New Zealand.

Why was it selected for use in Australia?
RHDV1 K5 was selected for release in Australia because it can overcome the protective effects of the benign calicivirus (RCA-A1) which naturally occurs in the feral rabbit populations in both Australia and New Zealand better than other strains of European rabbit calcivirus.

Why replace the existing virus?
Replacing the existing virus with a new strain may help overcome resistance to the old virus.

How widespread is this resistance?
Very widespread.

Can this strain infect other species?
No. RHDV1 K5, like other RHDV1 variants, only infects the European rabbit and no other species.

Will there be any human health effects?

What will this strain achieve?
RHDV1 K5 is expected to boost the effects of the existing RHDV1 strain and help slow the increase in rabbit numbers.

How can pet rabbits be protected?
There is a vaccine to protect pet rabbits. The Ministry for Primary Industries will confirm that this vaccine will be effective against the new strain.

Why is controlled release important?
Controlled release will ensure that a higher quality commercially prepared product is made available and that the release can be appropriately managed and monitored. This approach will increase the likelihood of success and maximise benefits to farmers and the environment.

Will this strain get rid of the rabbit problem forever?
No. A long-term, integrated approach to controlling pest rabbits is required.

Do all required approvals need to be received before release in New Zealand?
Yes. See below.

When is release in New Zealand likely to happen?
In the middle of this year – see below.

The New Zealand Rabbit Coordination Group (RCG) is co-ordinating the approvals processes. RCG includes representatives from Regional and District Councils, Federated Farmers, the Ministry for Primary industries and the Department of Conservation, and Land Information New Zealand. The applicant for the approvals on behalf of the RCG is Environment Canterbury.

Three statutory approvals are required to register, import and release RHDV1 K5 in New Zealand:
• A Hazardous Substances and New Organisms Act (HSNO) approval
• Registration under the Agricultural Compounds and Veterinary Medicines Act (ACVM)
• An unwanted organism permission under sections 52 and 53 of the Biosecurity Act (BSA).

The programme is targeted towards release in May/June 2017. This aligns with the proposed Australian release and is also when biological conditions are likely to be mmost favourable for RHDV1 K5.

Controlled release window is critical to fully unlocking the benefits of the biological control and will minimise the risk of potential illegal and/or uncontrolled releases. This will also ensure that a higher quality commercially prepared product can be made available and that the release can be appropriately managed and monitored.

A HSNO application was submitted to the Environmental Protection Authority (EPA) in September 2016 and is currently being processed. The required applications for the ACVM and BSA approvals will be submitted in February 2017.

The approvals process is being run in parallel with a Landcare Research Sustainable Farming Fund project to prepare a release strategy for RHDV1-K5. This will help participating Regional and District councils to effectively release RHDV1 K5 in rabbit-prone areas of New Zealand. The strategy will also include pre and post release monitoring to measure impacts and inform future research.