Vaccine-in-a-potato seems to work

The idea of using genetically modified plants to produce medicines for humans seems to be becoming a reality. In a new study, US researchers show that a hepatitis B vaccine can be delivered using genetically engineered potatoes, and it produces an increase in antibodies against hepatitis.

"Introduction of an oral vaccine for HBV could greatly impact global immunization acceptance," Dr. Charles J. Arntzen, from Arizona State University in Tempe, and colleagues note.

"We are greatly encouraged that this prototype study of human immunization against (hepatitis B) gave a strong and sustained systemic antibody response in about 60 percent of the volunteers who ate transgenic potatoes," they say.

The study involved 42 previously vaccinated individuals who were randomly assigned to take two or three doses of potatoes that produced a hepatitis B antigen called expressing HBsAg, or regular potatoes. The results are reported in the Proceedings of the National Academy of Sciences.

An increase in HBsAg titers was noted in 10 of 16 (63 percent) the volunteers who got three doses, and in 9 of 17 (53 percent) of those given two doses, but in none of the 9 who were given the normal potato.

The researchers say the results "provide compelling evidence" that oral vaccines can be a useful component of programs aimed at preventing intestinal and non-intestinal diseases.

SOURCE: Proceedings of the National Academy of Sciences Early Edition, February 14, 2005.