Although human trials are still needed, Daniell is confident the vaccine will work for the bubonic and pneumonic plague based on animal studies. Pneumonic plague is spread through the air. Without treatment a person can die within days. Bubonic plague is the more common form and is transmitted through fleabites and kills about 70 percent of those infected within 4-7 days if not treated. It was the version that ravaged Europe. If the early findings hold true, this vaccine could mean an extra layer of protection against natural epidemics and man-made threats.
The Centers for Disease Control lists the pneumonic plague as a potential bioterrorism agent because of the speed of which it can be spread and its 60 percent fatality rate if not treated early enough with an aggressive array of antibiotics.
Daniell was inspired to investigate an oral vaccine for the plague because of his pioneering work in diabetes. He and his team genetically engineered tobacco and lettuce plants with the insulin gene and then administered freeze-dried plant cells to five-week-old diabetic mice for eight weeks. By the end of this study, the diabetic mice had normal blood and urine sugar levels, and their cells were producing normal levels of insulin.
Daniell figured the same approach might work with a vaccine. He genetically engineered plant cells with a protein found on the outside of Yersinia pestis. The vaccine was inside the plant cells, which were given to the rats. The vaccine was protected from digestion in the stomach and was then absorbed in the gut. It kick started the immune system into producing antibodies, which protects against the deadly disease. Three to five doses seem to do the trick.
Daniell, who was born and raised in India, has dedicated his life to finding treatments and cures to diseases tha
|Contact: Zenaida Gonzalez Kotala|
University of Central Florida