Ranchers want old vaccine back
by Cat Urbigkit, Pinedale Online!
June 19, 2008
Twenty years ago, it wasn’t unusual for wild elk to enter cattle feedlines on private ranches in western Wyoming as winter storms raged. Many ranchers were aware of the threat of transmission of the disease brucellosis, and voluntarily vaccinated their cattle with the Strain 19 vaccine to provide protection to their herds. In fact, they “bootlegged” Strain 19 into the country before it was legal for use here.
But Strain 19 was problematic because it could cause “false positive” reactions on blood tests. Animals that tested positive for the disease would have to be slaughtered and their tissues cultured to determine if they actually harbored the disease.
Brucellosis is a highly contagious disease that affects a wide variety of species including cattle, bison and elk. It is incurable and can have a long incubation period, which can allow it to “hide” in the reproductive tract of an infected animal without being detected. Because of the human health risk associated with the disease, there has been a national program aimed at eradicating it for many decades. The human form of brucellosis is still a worldwide health issue and more primitive countries have entire hospital wards dedicated to caring for people afflicted with the disease.
Just over a decade ago, federal animal health officials determined that a new cattle vaccine, RB51, was better than Strain 19. RB51 offered the same immunity level as Strain 19, but wouldn’t cause the false positives. The USDA Animal Plant Health Inspection Service banned the use of Strain 19, so the nation’s cattle industry began widespread use of RB51.
Sublette County ranchers told animal health officials Tuesday evening in Pinedale that RB51 hasn’t lived up to its promises: it appears to provide short-term immunity, but unlike Strain 19, RB51’s protective effect appears to wear off in a few years – something not even researchers knew about. Even though elk are now actively kept off cattle feedlines, there have been several outbreaks of brucellosis in western Wyoming cattle herds since the use of RB51 was mandated. Last week, two cows from a Sublette County herd were determined to have contracted brucellosis.
Pinedale rancher and Wyoming Livestock Board member Albert Sommers told Tuesday’s gathering, “When APHIS took Strain 19 away from us, it created this issue.”
Boulder rancher and Sublette County Commissioner Joel Bousman agreed, urging APHIS to allow western Wyoming ranchers to go back to using Strain 19 because of the extraordinary circumstances in this region, where elk and bison serve as a reservoir for the disease that had been eliminated in the nation’s cattle herds.
Bondurant rancher Kevin Campbell said: “You folks have created a hell here in Sublette County ... False positives are better than having brucellosis.”
Daniel rancher Doug Vickrey noted for those who used Strain 19 before vaccination was mandatory: “We ran with the elk, sometimes year-round, and didn’t have a problem.”
Wyoming State Veterinarian Dr. Walt Cook said he would consider the possibility of requesting APHIS allow the use of Strain 19 in this high-risk region, since there is a mechanism in place to consider special rules. The issue is expected to receive more attention in coming weeks as state and federal officials undertake a massive brucellosis testing program for Sublette County cattle that might have come into contact with the herd where the infected animals originated. The entire herd of origin was being tested for brucellosis on Wednesday, and testing of neighboring herds was being organized as well.