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PCV2 vaccines - progress on the EU front 12 Jul 2007

Author: David Burch

At last, there has been some reported progress on the PCV2 (porcine circovirus) / PMWS (post-weaning multisystemic wasting syndrome) vaccine front in Europe.
At the recent International Symposium of Emerging and Re-emerging Pig Diseases, held in the delightful and historic city of Krakow in Poland the latest information on porcine circovirus vaccine development in Europe was revealed.
Quim Segales from University of Barcelona, Spain, demonstrated the protective effect of Intervet's piglet vaccine, Porcilis PCV® in an artificial infection study. The vaccine was given twice to colostrum-fed piglets and gave a high level of protection against a virus challenge from EU and US PCV2 isolates.
European fields trials
Successful European field trials, which mirrored earlier findings in N. America, were carried out with Boehringer Ingelheim's Ingelvac CircoFLEX®, a single dose piglet vaccine.
British consultant practitioner, Nigel Woolfenden, described a blinded, fully controlled study where piglets were vaccinated or injected with a placebo at 3 weeks of age and moved to the nursery at 4 weeks after weaning. Mortality from PMWS, in the enzootic pneumonia and PRRS-free farm was reduced from 14.3% to 4.6% (-9.7%) between weaning and slaughter and the surviving pigs weighed 6.8kg heavier than the placebo controls.
The onset of the PCV2 viraemia and the start of the detrimental effects occurred at approximately 8 weeks of age. In a similar German study, Mathias Ritzmann from Ludwig Maximilian's University, Munich reported on a trial in a multi-sourced growing/finishing herd with mixed PMWS and porcine respiratory disease complex (PRDC) problems. The viraemia started at 11 weeks of age and peaked 2-3 weeks later. The viraemia coincided with a divergence in growth rate between the vaccinated and control pigs. At the end of the study, the mortality was reduced from 9.4 to 5% (-4.4%) and the pig's bodyweight was 4.6kg heavier.
Merial celebrated, during the conference, the announcement that their PCV2 vaccine for sows, Circovac®, has now received EC approval and should be available across the EU fairly soon. This is the first EU approval for a PCV2 vaccine. The vaccine should stabilize sow herd immunity and give protection of the piglet for up to 5 weeks after the transfer of passive antibodies to the piglets through colostrum uptake. Thereby, lesions in lymphoid tissues and mortality associated with PCV2 infection should be reduced.
At long last, with this exciting new PCV2 vaccine information coming through in Europe, we are catching up on the N. Americans and soon we will have the tools to control this depressing circovirus wasting disease.

Comments (2)

1.
Hi, may i know is there any value to vaccinate a herd that already tested sero positive for PCV2?? In an herd of pigs that already infected with Circo virus, isnt that by it self, they can develope the immunity and we inroduce the antigen to an infected herd, can it be considered as pouring the salt into the sea??? can anyone clear my quries?
Lee. C. S at 14-09-2007 11:39
2.
We have entered the chronic phase of the disease in the UK. In PCV2 infected herds, maternal antibodies fade by 8-10 weeks althought the infection has been shown to be in the nose of the piglet from the first week of life. Once the MDAs have gone there is a natural viraemia (virus multiplying in the blood). Most pigs will respond to the infection and recover but some pigs are overwhelmed by the viral challenge and will go on to develope the various forms of PMWS or wasting, even death. A number of factors are involved which assist the virus to replicate and overwhelm the immune system. Piglet vaccination has proven extremely successful in protecting against the later stage viraemic attack.
David Burch at 26-09-2007 10:57

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