Enough anthrax vaccine to inoculate everyone in the United States could be grown inexpensively and safely with only one acre of tobacco plants, a University of Central Florida molecular biologist has found.
Dr Henry Daniell, a native of Chennai, India and currently a professor of Molecular Biology at the University of Central Florida, has successfully found a safe and effective method of producing large quantities of vaccine for anthrax. The new production method also could help the government and health care providers avoid supply shortages, as one acre of plants can produce 360 million doses in a year.
"Anthrax vaccine is very much in need, primarily because of bioterrorism concerns," Daniell said. "But in the United States, only one company has the capacity to produce the vaccine, and it is made in very small quantities by fermentation. We can provide enough doses of a safe and effective vaccine for all Americans from just one acre of tobacco plants."
Current production of the vaccine involves an expensive fermentation process that can cause harmful side effects such as inflammation, flu-like symptoms and rashes. This has prompted some people to refuse to be vaccinated.
Seeking a safer and more effective alternative, Daniell and his colleagues injected the vaccine gene into the chloroplast genome of tobacco cells, partly because those plants grow much faster than carrots, tomatoes and coffee. They grew the cells for several weeks in Daniell's laboratory. Tests showed the vaccine taken from the plants was just as potent as the one produced through fermentation and lacks the bacteria that can cause harmful side effects.
Researchers then injected the vaccine into 35 mice to immunise them against anthrax and sent the mice to the US National Institute of Health labs, where they survived doses of anthrax several times stronger than the amounts to which humans have been exposed.
The next step for the anthrax vaccine would involve a company working with NIH to conduct clinical trials. Human subjects would be injected only with the vaccine and not with anthrax itself, and scientists would then check the subjects' immunity levels. The vaccine later could be mass-produced and stockpiled for emergencies.
Professor Daniell conducted his study with part of a $1 million (about Rs 4.5 crore) NIH grant and a $2 million (about Rs 9 crore) US Department of Agriculture grant that cover research related to genetic engineering in plants as a way to produce therapies for several diseases. Daniell's work holds promise for treating other diseases, including diabetes and hepatitis, and improving vaccines for plague, cholera and other bioterrorism agents. He said he was inspired to work on the vaccines to make them affordable for the poor in India and other countries globally.