Scanning results from flocks in two Welsh counties with the highest concentration of sheep suggested the vaccine had no impact on sheep miscarriages.
In fact, scan results indicated abortion levels were particularly low, Estyn Jones, chairman of NFU Cymru’s Brecon and Radnor branch, said.
Speaking to the branch’s annual conference at Builth Wells, Mr Jones said rumours the vaccine led to increased abortions in flocks were “unfounded”.
He urged farmers to vaccinate against the disease and to show the Welsh Assembly “we can get the job done”.
Brecon farmer Meredydd Jones told the meeting that he was disgusted about the way other farmers had imported the disease.
“We need to look in the mirror and tell ourselves that we have to prevent this terrible disease from reaching our flocks in Wales,” he said.
Meanwhile Huw Brodie, rural affairs and heritage director of the Welsh assembly, said all farmers should heed the message issued by rural affairs minister Elin Jones and vaccinate.
He also warned that only a miracle would stop the imposition of EID, but the assembly was committed to helping Welsh farmers make the best of a bad job.