Oral transgenic plant-based vaccine for hepatitis B.

In addition to improving vaccine formulations in order to elicit robust and long-lasting immune responses, there is also an increasing need for improving the manner in which these vaccines are delivered. As most current vaccines are administered by injection by a health care giver, there is the ever-present danger of needlestick injuries. Therefore, needle-free vaccinations are a viable option toward limiting needle-associated injuries and additionally increasing compliance with vaccination schedules, as both children and adults have an aversion to injections. Noninvasive methods of vaccination will also facilitate speed of vaccine delivery and likely also reduce cost, both important factors for health care in developing countries. One alternative to current injectable immunizations is orally delivered vaccines. A specific approach that we and others are evaluating is the use of transgenic plant tissue that expresses vaccine antigens for oral immunization. Herein, we review the development of an oral HBV vaccine expressed in transgenic potato tubers and the immune responses generated in human subjects given this novel vaccine.