August 22, 2008

A new vaccine from Imugene promises a "very high degree of protection" against PRRS.

Preliminary results from the company's recently completed trials in the US showed that the vaccine is particularly effective when two doses are administered either orally or by injection.

Porcine Reproductive and Respiratory Syndrome (PRRS) is caused by a viral infection. The major clinical signs are the result of areas of diseased lung (consolidation). To evaluate the severity of an infection, standardised lung lesion scores are generated by scoring the diseased areas in each of the 7 lung lobes from each pig.

The lower the average lung lesion score, the lower level of disease. Since clinical illness slows weight gain during and after infection, an effective vaccine should also result in less clinical illness and therefore better weight gains following infection.

Results of the trails showed that vaccinated pigs challenged with the live PRRS virus had much lower lung lesion scores and better weight gains over the 14 day post-challenge period compared to the unvaccinated control pigs.

The trials were undertaken at a specialist trial facility in the US. A full trial report is being prepared and is expected in the next 4-6 weeks.

Imugene will use these results in discussions with major animal health companies to work out licensing deals.