6 June 1997

Vaccines offer improved pasteurella protection

By Emma Penny

IMPROVED protection against pasteurella will be offered by new vaccines due to be launched in July.

The vaccines, developed by the Moredun Research Institute, Edinburgh and Hoechst Roussel Vet, promise better quality protection as well as protection against an extended range of pasteurella strains.

The improvement is due to the use of iron regulated proteins (IRPs). These antigens – which stimulate antibody production – improve protection against the nine strains of pasteurella included in current vaccines and also provide cross protection against other strains.

The new vaccine will replace current stocks of Heptavac-P, Ovivac-P and Ovipast, but price will remain the same for the comparable products Heptavac-P plus, Ovivac-P plus and Ovipast plus.

Like all dead vaccines, sheep will require two doses of the new vaccines four to six weeks apart to ensure they benefit from the enhanced protection.

According to Hoechst Roussel Vet sheep vaccine product manager Geoff Hooper there are two options for use – phased or rapid conversion.

"In a phased conversion, producers would vaccinate replacements with two doses of the new products, ensuring better pasteurella protection.

"The main flock would be dosed with these as usual – as single vaccination before lambing. They will be protected to the same standard as previous vaccines but will not benefit from the enhanced protection."

But where pasteurella has been a concern, producers could opt for the rapid conversion, ensuring all ewes received a double dose of the Plus products four to six weeks apart, he says.

"Producers could give two doses of Plus vaccines in the autumn, followed by the usual pre-lambing booster. Alternatively, ewes could be given a double dose in spring; a single dose of Ovipast Plus about 10 weeks before lambing followed by the annual booster of Heptavac-P Plus four to six weeks before lambing."n