CIWF sponsored conference at Bristol University Sept 15 - Chairman Bill Eykyn
Joyce de Silva, the director of Compassion in World Farming, opened the forum with remarks about the ethical considerations of the slaughter policyand the many bad examples of culling that have been reported, the cost to the humans who have had to be involved in the cull and the cost to the animals themselves.
Wendy de Vere,, whose idea the conference was, explained that as a vet in Devon watching the slaughter,she had - in mid April - 5 questions she wanted answered by Defra :
Why weren't sheep being serologically tested?
Why weren't local vets being used to assess local risks?
Why weren't they being used to prioritise welfare cases?
Why was the delay between diagnosis, slaughter and disposal stretching into days and weeks?
Why were contiguous premises being killed out long after the incubation period?
A partial reply to these questions did not come until 24th August (i.e. four months later). She decided that since communication was so bad vets needed to find out answers for themselves..Does vaccination work against FMD? How does it work? She was also gravely concerned about the moral and ethical obligations owed by the veterinary profession. Consequently, she conceived the idea of the conference, which was sponsored by Compassion in World Farming and organised by Alicia Eykyn.
Dr Peter Poll, from Utrecht, explained to the audience how, sickened by the destruction in Holland, he proposed to the Dutch College's AGM on 6th October that in view of the proven efficacy of vaccination, if a non-vaccination policy is continued with its unacceptable consequences for animals, farmers, veterinary surgeons and many others that "we will no longer cooperate in an eradication programme as carried out in Spring 2001" He said he was optimistic that his motion will be accepted.
Ken Tyrrell, the Shropshire vet said"Those of us who were involved in the 67/68 outbreak can only watch the dreadful mistakes appearing on our tv every day with a mixture of absolute horror and dismay..."
Professor Fred Brown explained the molecular structure of the virus and then showed the "Smart cycler" device for rapid diagnosis. This was the machine commended to the British Government as long ago as 9th March - but has never been adopted or even investigated. Its main features are
- Making a sample safe to handle to a local mobile analysis lab
- Freedom from contamination - analysis in a clean environment
- Speed. The results can be obtained in 40 minutes
Dr Simon Barteling, an international consultant on FMD has been the Head of Department of vaccine production and research as well as the head of the EU Community Co-ordinating Institute for FMD.He was instrumental in the fight for vaccination in Holland. He compared very fully the relative advantages and disadvantages of culling and vaccination, dwelling particularly on the contamination issues and the distress of farmers who are involved in a cull. He admitted that if a vaccination team enters a farm while there is already disease it cannot be prevented from becoming full blown. Full protection begins after three days and the last case will appear about 5 days after the end of the vaccination. But the advantages include the small number of people needed. They can be easily and fully briefed. Working from outside to inside the disease can be contained. It is relatively cheap so preventive action can cover larger areas than the culling ones including all possible contacts. Restocking with vaccinated animals can happen quickly and after 2-3 weeks normal life can start again. "The message is it works - and Brussels knows very well that it works." The EU Commission is very fast in offering vaccines (Bulgaria, Albania Macedonia 1996) if FMD happens near its borders. Culling did not work in south Africa. When it was seen to be out of control vaccination was started and it worked. He explained what a bitter blow it was to find that the successful protective vaccination policy, resulting in a complete cessation of cases after 5 days was suddenly changed to "suppressive" policy by the dutch government and the animals ordered to be killed - to the great dismay and incomprehension of their owners. "The big question is why?" He explained that the worry about the presence of antibodies is illogical since there are still many seropositive animals in Europe left over from before the policy change in 1991. Such "carrier" animals might possibly be a threat in the winter months but there is no single example of a vaccinated animal has caused new disease. In the past billions of animals have been vaccinated both in Europe and in South America. He ended by asking what are the rights of farmers? Farmers should be able to feel that rules are made in a justifiable manner - which is not the case now. On the international scene, the consequences of ring vaccination should be identical to that of slaughter. With ring vaccination you may make some carriers but they have not beeen proved to be dangerous ; without vaccination you also have carriers who may be infectious but they get no attention. The consequences for FMD status with ring vaccination and with slaughter should be the same.
Dr Paul Sutmoller spoke in detail about his highly successful work in South America. He said his object was to demystify vaccine - and this he did.Vaccine proves to be very stable under refrigeration. The duration of immunity was longer with oil-based vaccine than the earlier ones and revaccination provides long immunity. Vaccine proves to be very stable under refrigeration. The duration of immunity was longer with oil-based vaccine than the earlier ones and revaccination provides long immunity.
The development of the modern oil-based vaccines was explained and Dr Sutmoller compared their improved performance to those previously available. He said there was such an excellent response in pigs in the production of antibodies, that fattening pigs were protected by a single dose, and sows (who are allowed to live longer) are protected by an annual dose. He gave an example the vaccination of five thousand pigs on a farm where disease was endemic. There was no further outbreak within five days. Obviously, some of these pigs were incubating disease at the time of the injections, but vaccination still worked. Sheep responded better than cattle, with higher antibody levels and better resistance to direct contact with live virus. Cattle over two years old require an annual injection, younger stock twice yearly.
1977 was a significant year in the development of vaccines. In a field trial, 23 farms holding 36,000 cattle were vaccinated in a ring around infected farms; none of these animals became infected. Farmers were impressed. Up to this point, FMD control had used: *vaccine of poor quality
*low vaccination coverage of population (without farmer co-operation)
Many of the current misconceptions about the efficacy of FMD vaccine date from this earlier time. Once farmers had seen the new vaccines act effectively, they demanded their use and FMD morbidity in cattle fell dramatically, e.g. from 19.9 per 10,000 head in 1981 down to zero by 1995 (Argentina). In Uruguay, a two-year vaccination programme (in cattle only) eliminated FMD; vaccination ceased and there followed six years without any disease. The same pattern was repeated in Brazil and Argentina.
Dr Sutmoller conducted research that sought to prove the possibility of transmission from "carrier" animals to healthy ones. An extensive series of elaborate experiments, far more challenging than any farm situation, was unable to show that such transmission occurred in cattle or sheep, while pigs do not become carriers.
He said, quote "All experimental evidence of FMD virus transmission by carrier sheep is negative". He went on to say that vaccinated carriers had posed no problems during FMD eradication in South America. Finally, he pointed out that scientifically there was no risk of exporting FMD in vaccinated meat, whereas FMD-free status meat carried the risk of undetected disease.
(Thanks to Alan Beat for assistance with Paul Sutmoller notes)