MANHATTAN -- For Kansas cattle, getting vaccinated may become as simpleas eating fodder. Researchers at Kansas State University are developing avaccine for calf enteric disease that will not be delivered as a shot. Itwill instead immunize cattle through the alfalfa they eat.
Sanjay Kapil, assistant professor of diagnostic medicine, heads theeffort to genetically express proteins for the bovine corona and bovinerota viruses in plants. With traditional vaccinations, farmers directlyinject cattle with non-infective virus protein. This produces antibodiesthat help fight disease. However, Kapil explains that this process is ahassle for ranchers.
"If you inject too much of the virus, the cattle will get sick. But bydelivering vaccines with plants, the cattle will never get sick." This isbecause the plant vaccines do not have concentrations of infectiousvirus. Anyone who has struggled with capturing and injecting a calf witha needle will recognize the convenience the new vaccines will provide.
Researchers must first insert the genes of the virus into the plantchromosomes so that it will become a permanent part of the plant'sgenetic code. The ultimate goal is expressing the new vaccination gene insuccessive generations of plants, which can then be fed to animals.
Kapil explains that smaller trials represent the first step in theoverall process. "Before we go into large scale animal trials, we need todo it in a lab system. So we chose tobacco plants and the mouse, whichare easier to work with in the lab." The team has successfully integratedthe vaccine in tobacco plants and fed those plants to mice. Now, they aresimply waiting for the results.
Though the Kansas State team moved first in bovine vaccinations,researchers had already begun expressing vaccination genes in plants forhuman consumption. Knowing the results of their trials, Kapil expects thesame positive results for cattle. The next step will be actual fieldtrials, taking vaccines into fodder crops, like alfalfa, and giving it tocattle. Field trials could be as little as five years away.
Plant vaccines will help Kansas farmers and ranchers, but thesignificance of this research stretches far beyond its cattle ranches.Enteric diseases like corona and rota cost more than $3 billionworldwide, infecting and killing young cattle with diarrhea. Ranchers inthe United States lose $250 million annually to the viruses.
Kapil expects this research to help many related projects.
"We have crossed the boundaries of just the animal group." He explainsthat a similar rota virus invades human babies, as well as cattle,leading to infection in 750 million children each year. If the bovinevaccination proves effective, a similar technique may be developed forchildren.
Because of this exciting potential, the K-State team is applying for apatent. While similar procedures have been patented, Kapil feels this histeam's genetic engineering is unique. "Every system is different: whichgene to go after, how to deliver it, which crop, how to deliver it in thecrop. We're very lucky. The initial results are very promising."
Kapil says his team's research is "a storybook of daydreams." For cattleand farmer alike, gene vaccines would be a dream come true.
Materials provided by Kansas State University. Note: Content may be edited for style and length.
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