Does NZ need a GM horse vaccine?

June 19, 2008

It has been called the silver bullet - the vaccine that turned the tide on Australia's equine influenza outbreak and led to its eradication.


The equine influenza virus
Within days of Australia announcing its intention to declare itself formally free of the disease, New Zealand's Environmental Risk Management Agency (ERMA) received an application for conditional approval to use the same Proteqflu vaccine.

Does New Zealand need this genetically modified vaccine and what risks are inherent in its use here?

The Green Party has been quick to condemn the move. It argues there will be huge risks through a lack of containment and it would kill the country's GE-free status.

"I am amazed that for the benefit of Australasia's gambling industry we are putting our GE-Free status at risk," says party co-Leader Jeanette Fitzsimons.

"Of course, we already have genetic engineering here but the Green Party has been successful in keeping it in the laboratory or under strict control in field trials. We can still boast our farms and environment are GE-free.

"There is already a vaccine for horse flu approved for use here, and the only control proposed for the GE vaccine is that it be administered by a vet. It is proposed that there should be no monitoring of the outcomes."

However, the New Zealand Racing Board (NZRB) and the New Zealand Equine Health Association (NZEHA), both of which are seeking approval for Proteqflu's use, argue it would be the most effective tool available to fight any equine flu incursion in New Zealand.

It confers immunity on horses quicker than any other equine flu virus and the wider risks from the genetically modified canary pox virus which forms the key component of the vaccine are low.


Does New Zealand need the genetically modified Proteqflu vaccine, and what risks are inherent in its use here?
They propose its use only in the event of an outbreak and for horses bound for export markets where inoculation with this vaccine is mandatory before entry.

The NZRB and NZEHA, in their 111-page application, spelt out the cost of the Australian incursion - $217 million in compensation and relief payments and a further $150m in eradication and containment costs, as well as the crippling effect on equine industries.

Direct costs of an outbreak to the New Zealand equine industry are estimated at $167m and the impact to the economy based on the current economic contribution that the equine industry makes to the economy could be as high as $500m over a four-month period.

If the disease was not quickly eradicated there would be ongoing economic impacts, especially to the breeding and export sectors.

"More than 40,000 people derive their livelihoods from the equine and racing industries in New Zealand," the applicants said. "Racing alone generates more than $1.4 billion in economic activity each year and creates 18,300 full-time equivalent jobs.

"The export sale of horses generates more than $120m each year and more than 4700 horses travel between Australian and NZ each year.

"If an EI outbreak was to occur in New Zealand it would cause a nationwide shutdown of all horse racing, eventing, pony clubs, horse sales and other equine related activities.

"There would be an immediate suspension of all horse movements, both domestically and internationally. This would cause major disruption to the earning steams of industry participants, many of whom live week to week.

"It would severely compromise New Zealand's breeding industry and the export sale of horses reducing tax revenues and the contribution to the local and national economy."

The NZRB and NZEHA said Proteqflu is seen as the vaccine most likely to minimise the impact of an EI outbreak to the economy.

"It is the vaccine of choice internationally, it takes rapid effect and immunises against multiple strains of the EI virus. Proteqflu creates an immune effect in the horse within 1014 days of administering; this is a third of the time of any other vaccine."

It has no unexpected side-effects and equine flu tests can differentiate between the wild virus and the vaccine virus.

The vaccine, they said, is considered the single most important factor in controlling the Australian outbreak.

"Because equine influenza has never occurred in New Zealand the whole horse population is highly susceptible to the disease.

"In the event of an outbreak the industry and MAF Biosecurity would work together to try to eradicate it, and the best tools would be needed. Proteqflu has been shown in the Australian situation to be an ideal tool."

The application was described as a pro-active step by the industry to be prepared should an outbreak occur.

So what is the vaccine? The application covers Proteqflu and Proteqflu TE, which covers tetanus as well as equine influenza.

The vaccines are based on a non pathogenic strain of the canary pox virus which is said not to replicate in any mammalian or human cells so once it is injected into the horse, it dies out. Thus, the applicants argue, it poses no risk to public health or the environment.

"Proteqflu and Proteqflu Te are not pioneering vaccines; their safety and efficacy has been mirrored in other vaccines which have been researched and others which have been approved for use in animals.

"These include West Nile vaccine for horses, Rabies vaccine and FeLV vaccines for cats and distemper vaccines for dogs and ferrets. These vaccines are listed by the European Medicine's Evaluation Agency (EMEA), and the Canadian Food Inspection Agency and approved by the US Food and Drug Administration (FDA).

It is proposed that the vaccine will be held in cold storage in Auckland in a MAF-approved facility either until their expiry date or until they are used.

"Should an EI incursion occur, the situation would be under MAF Biosecurity New Zealand's control.

"The vaccine would be used as a tool to assist eradication in the short term; some sectors of the equine industry would seek wider use to protect their industries, as did the racing industry in Australia.

"In this situation it is proposed that all horses which were vaccinated would be identified by brands or microchips.

"Finally, if equine influenza was seen to be of too high a risk to the New Zealand equine and racing industries and the outbreak was unmanageable and EI was endemic, consideration would be given to making the vaccine freely available.

"This would only happen if an EI incursion spread so rapidly through New Zealand that it could not be contained. A decision to this effect would be made by MAF Biosecurity in consultation with the racing and equine industries, taking into account all the information available at the time."

The applicants acknowledge that use of the vaccine would affect New Zealand's GE-free status.

"Proteqflu and Proteqflu Te will be the first genetically modified organism (GMO) to be released into New Zealand and concerns will be raised by the public.

"However, certain GE food is already permitted in some processed food lines in New Zealand Once the horse has been vaccinated with the GMO vaccine, the recombinant virus dies out and therefore there is no risk of a GMO organism surviving in New Zealand."

Having an approved vaccine means there would be no delays in vaccination while waiting for regulatory approval.

"This means horses are protected sooner, events can recommence earlier and the economic losses contained. Proteqflu is relatively more effective in terms of time to vaccinate and the time it takes for the vaccine to stimulate an immune response.

"These factors mean that the virus can be more rapidly contained using Proteqflu when compared to the currently approved vaccines.

"Another critical advantage is that the Proteqflu and Proteqflu Te vaccines are the only vaccines worldwide that meet the recommendations of the OIE [World Organisation for Animal Health] Expert Surveillance Panel for vaccines for Equine Influenza.

"Proteqflu and Proteqflu Te vaccines currently contain two strains which are considered to protect against all currently circulating EI strains. "Theoretically vaccination could therefore start the day a case of EI was confirmed whereas under the current MAF response/registered vaccine vaccination will not start until the exact vaccine strain is confirmed."

They continued: "For New South Wales, Proteqflu and Proteqflu Te were almost the 'silver bullet' in the eradication of EI. Movement control and Biosecurity were other important tools. New Zealand has learned from the Australian experience and needs to be prepared. These vaccines are an essential tool in protecting a significant New Zealand industry."

The practical risks associated with the introduction of Proteqflu and Proteqflu Te would be negligible, the applicants argued.

The application is subject to full public consultation and a public hearing will be held if requested by submitters. The deadline for public submissions is July 29.

The Green Party's Fitzsimons says the application will come under the greatest scrutiny.

"ERMA and submitters must scrutinised the evidence for these claims very carefully. We need to know what tests have actually been done, and the full results must be released publicly. We can't afford to be wrong.

"The applicants have claimed that the new virus can't multiply in mammals, including the horse, and that it dies after a day. They also claim the host virus is stable. However, that doesn't mean the modified virus is.

"All GE organisms raise the possibility of horizontal gene transfer where genetic material from one species jumps across to another unrelated species, by a process other than usual reproduction.

"Can this happen inside the horse, and affect a longer-lived virus, which perhaps then infects other animals?

"It seems incredible that with our experience of rabbits, possums and didymo, ERMA could approve a GE organism throughout the land without thought of long-term consequences. Why pick an invisible little virus that we can't find if we need to?

"If the government is so keen to destroy our GE-free status, my choice would have been something we can actually keep track of, like an elephant."