What Is The AUSVETPLAN?

“Australia’s response to a range of emergency animal diseases is captured in a series of technical and scientific response manuals called AUSVETPLAN”.

Given that the debate regarding to vaccinate or not to vaccinate is hotting up, it seem a good time to explain very briefly what is contained in the AUSVETPLAN regarding the outbreak of EI.

“In terms of EI, the Ausvetplan states that vaccination will not be used if an EI outbreak is detected early and can be confidently contained by effective movement controls. However Ausvetplan recognises that vaccination may be appropriate where:

The disease is widespread when detected; or,

Significant numbers of horses are at immediate risk; or,

Initial control methods have failed, and the disease has spread beyond the original restricted area and is likely to become endemic in the general equine population.

AUSVETPLAN identifies the following strategies for the use of vaccination in the face of an outbreak:

Mass vaccination – this would involve widespread vaccination of horses to build up herd immunity.

Ring vaccination – vaccination is carried out locally in a ring around identified sources of infection to limit further spread by producing an immune buffer.

Predictive vaccination – this targets enterprises and populations that could be expected to contribute most to future spatial transmission of infection.

Advantages of Vaccination.
Vaccination can prevent clinical disease.
Vaccination reduces the susceptibility of at risk horses, reduces severity of clinical signs and the level of viral shedding if they become infected.
Vaccination can reduce farm to farm infection.
Apart from horse movements to New Zealand, there are unlikely to be any international implications of vaccinating.

Disadvantages of Vaccination.
Vaccination may mask clinical signs, so vaccinated horses will need to be identified and monitored for evidence of infection.
Serological monitoring will be difficult, even though tests are available to differentiate vaccinated horses. Some tests used in this respect may not be internationally validated.
The movement of sub-clinically infected, vaccinated horses, may spread infection to previously unaffected areas.
Vaccination may prolong the need for movement restrictions, because it may slow the transmission and spread of infection within areas.
Vaccinating selected regions will lead the country being separated into free and vaccinated areas. This will result in the differential movement requirements and the need for infrastructure (permits, border control etc.) to maintain integrity of free areas.
Vaccination will have an impact in terms of registration and passport issues and the practical control measures required before many horse events can proceed.
Vaccination is not an immediate option, it will take time to import vaccine (permit process), deploy vaccine and train vaccinators, vaccinate the population, for immunity to develop.
In the case of the recombinant (canary pox) vaccine there may be restrictions placed on how and who may use the vaccine.
Vaccination may affect performance in the short term.
Vaccine use is likely to extend the duration of the outbreak and delay ability to declare freedom”.

This table was produced by the Consultative Committee on Emergency Animal Diseases on the 13th September.

It really does look as if the CCEAD are throwing all they have into the NO vote for vaccination. The advantages sound pretty good though. There is not doubt that no flu vaccination gives 100% immunity, but reasonable immunity is better than none surely?

Much of the above “disadvantages” is old news now, but it is worth examining some of the disadvantages.
Identifying and monitoring vaccinated horses can surely not be that great a problem. Most horses are registered with some organisation or other, even foals.

Testing whether a horse is positive because it is vaccinated and positive because it is sick with EI cannot be that difficult and if it is, there are tests to determine one from the other.

With some talk of restrictions still being in place next Easter, it is hard to imagine that a vaccination regime would be slower that that. It is hard to see how vaccination would extend the outbreak.

The canary pox recombinant vaccine is genetically modified and will not be accepted in WA and Tasmania, as veterinarian Denis Goulding explained last week. Denis also pointed out that and inactivated vaccination would be needed for horses to travel to Europe.

How much training does a veterinarian need to administer a vaccination?

Like humans after a vaccination, they may feel a bit off colour for a day or two, but any affect is very short term.

One argument against vaccination that appears again and again is that blanket vaccination does not prevent EI outbreaks and there are many examples of the outbreaks in Europe etc. But as has been discussed at some length in the article in the current issue of Horse Deals, entire countries are not shut down, and they are only little countries. If there is an outbreak in France they still have shows in Germany and Italy and that is because the horses are vaccinated. In 1992 there was an outbreak amongst the horses stabled at the Hong Kong Jockey Club. 37% of the 955 horses contracted the virus. Given the very close confines horses are stabled in Hong Kong, it would seem, whilst 37% would not please the vaccine producers it is a lot better than 100% which was the case at Randwick. And one would presume that the 37% did not suffer a serious bout. This statistic can be used for either argument.

However, eradication is by far the best way to go if it can be achieved.

Reference material.

National Management Group Communique 13th September.
Biosecurity Victoria ‘Vaccination Strategies for Equine Influenza’ Discussion Document.