Final steps in developing and testing a live attenuated JD vaccine for dairy cows


Source: RDAR

Developing a vaccine that is effective at controlling or eradicating paratuberculosis from the dairy industry is highly desirable.

The successful development of a vaccine will be a significant step forward, not only for the control of the animal disease and the associated production losses, but also for the reduction of the risk to humans due to transfer of infectious agents via food and water.

How will this research impact Alberta’s agriculture industry?

Alberta has a high prevalence of Johne’s disease (JD), a chronic intestinal infection caused by Mycobacterium avium subsp. paratuberculosis (MAP). This research fits in the desire of the dairy industry to reduce potential food safety risk by eliminating MAP from dairy product food supply.

Vaccination is a logical JD control measure, but the development of a quality vaccine has proven difficult. A live attenuated vaccine against JD is most promising to protect calves against MAP infections.

The advantage of using a vaccine to control JD is that the reduction in infections and consequently shedding of MAP on a farm will go down with every additional animal that is being vaccinated. In other words, vaccination is expected to have a positive cumulative effect on the burden of the disease on a farm.

Why did RDAR invest in this research project?

The proposed research benefits and fits in the desire of the dairy industry to reduce potential food safety risk by eliminating MAP from dairy product food supply. There is continuing concern that MAP might have public health implications. The associated risks can best be addressed by trying to control and eliminate MAP from the dairy industry. Elimination of
infection with MAP will also have important direct economical benefits do the dairy producers as even subclinical MAP infections in dairy cows lead to reduced milk production, reduced carcass weight, reduced fertility and increased culling.

How will research knowledge be transferred and shared with producers?

Knowledge generated from this project will be readily transferred through the members of the research team to the dairy industry, with an emphasis on the producers and their herd veterinarians. This research group has a strong relationship with the dairy industry in Alberta. Project researchers will strive to ensure that researchers, producers and professionals in the
Western Canadian dairy industry are beneficiaries of the novel and up to-date information gathered in this study and the actual vaccine. This team has demonstrated their research outcomes at the Western Canadian Dairy Seminar over the last several years.