Phase 1 trials of the the first human tests of a vaccine grown in tobacco plants proved that the vaccine against against follicular B-cell lymphoma were safe for patients. If further trials demonstrate its efficacy, this presents a novel method of producing vaccines quickly and cheaply.

The researchers chose tobacco plants that were genetically modified to reproduce quantities of the vaccine. To make a tobacco plant churn out a human antibody, scientists isolate the antibody from the patient's tumor and put the antibody gene into a modified version of the tobacco mosaic virus. They infect a tobacco plant with the gene-carrying virus by scratching the virus on its leaves. The virus takes the gene into the plant's cells, which then churn out lots of antibody. After a few days, technicians snip off the plant's leaves, grind them up and purify the antibody. Only a few plants are needed to make enough vaccine for each patient.

"The new manufacturing system allows very rapid production of a vaccine," said Charles Arntzen, PhD, a professor of plant biology at the Arizona Biodesign Institute at Arizona State University, who was not involved in the research. "I think without the speed, it would be hard to convince a cancer patient to wait for a vaccine to be developed, rather than going on some other therapy."

The study is published in the advance online issue of the Proceedings of the National Academy of Science.