Roswell Park Study Evaluates Oral Hepatitis B Vaccine

Newswise — An oral vaccine administered in genetically engineered potatoes shows promise against the Hepatitis B Virus (HBV) according to researchers at Roswell Park Cancer Institute (RPCI) and their colleagues at Arizona State University. The vaccine, which consists of only one protein from the virus, may be safer than other oral vaccines that use weakened living viruses. The research is published in the current issue of Proceedings of the National Academy of Science of the United States of America.

In a placebo-controlled, double-blind, Phase I study, 42 adult healthcare workers, who previously responded to a licensed, injectable vaccine, received an oral booster dose delivered in transgenic potatoes that expressed the hepatitis B surface antigen. Blood serum antibodies increased in 10 of 16 volunteers (62.5%) who ate three doses of potatoes and in 9 of 17 volunteers (52.9%) who ate two doses of transgenic potatoes. It did not increase in volunteers who consumed the non-engineered potatoes.

HBV is responsible for significant morbidity and mortality worldwide in spite of the availability of a safe and effective injectable vaccine. More than two billion people worldwide are affected by HBV, a leading cause of liver cancer and the cause of over one million deaths annually. Current vaccines are of limited availability and use in developing countries because of cost and the need for cold storage.

"There is an urgent need to make oral vaccines available in poorer countries of the world where infectious diseases are still the primary cause of death," said Yasmin Thanavala, PhD, Department of Immunology, RPCI. "This clinical study demonstrated the success of a prototype oral immunization process for HBV. It could be implemented cost-effectively throughout the developing world, thus providing a new strategy to solve a global problem."

Roswell Park Cancer Institute, founded in 1898, is the nation's first cancer research, treatment and education center and is the only National Cancer Institute- designated comprehensive cancer center in Upstate New York. RPCI is a member of the prestigious National Comprehensive Cancer Network, an alliance of the nation's leading cancer centers. For more information, visit RPCI's website at http://www.roswellpark.org, call 1-877-ASK-RPCI or e-mail [email protected].