Nasal Hepatitis B Vaccine Elicits Robust Immunity with a Single Dose; Confers Major Advantages over Traditional Vaccines

Ann Arbor, Mich. August 13, 2008 -- A new study has shown that a nasal hepatitis B vaccine elicits a dramatic immune response in animals without requiring three vaccinations, sterile syringes or refrigeration -- three factors that impede the delivery of current hepatitis B vaccines.

In the study, a single dose of the nasal vaccine triggered a protective response in animals roughly 450 times greater than that elicited by currently approved human vaccines. The animal studies demonstrate a magnitude of immunity that has not been seen in advanced preclinical testing of other nasal vaccines, according to the scientists at the University of Michigan and NanoBio Corp.

Moreover, the mucosal vaccine produced three distinct types of immunity --mucosal, cellular and systemic -- which enabled a rapid immune response that could kill virus-infected cells and prevent future infections. Traditional injected vaccines do not elicit mucosal or cellular immunity.

The study, reported in the online August 13 issue of the journal PLoS One (Public Library of Science), has critical implications for developing countries where hepatitis B presents a serious health threat, said James R. Baker Jr, MD, lead author on the paper and a founder of NanoBio Corp. NanoBio is a spin-out from the University of Michigan and has exclusive rights to commercialize the vaccine technology.

Developing nations have difficulty providing proper refrigeration, sterile needles or three separate vaccinations, as are currently required. As a result of these challenges and despite the existence of effective vaccines, more than 400 million children and adults worldwide are infected, and more than a million people die from hepatitis B each year.

"We have developed a new vaccine that is extremely safe, easy to administer, and which rapidly builds protection against hepatitis B infection," said Baker. "The same vaccine platform has also been shown to elicit significant immune responses in animal studies with influenza, anthrax, smallpox, RSV and HIV. Plans are under way to begin testing in humans."

The vaccine platform and its associated research, funded in part by the Bill & Melinda Gates Foundation, represents a major departure from traditional vaccines on numerous levels.

Among its unique qualities, the mucosal vaccines are delivered directly to the lining of the nose where immune cells recognize the foreign antigen contained in the vaccine. This rapid stimulation of the immune system does not involve inflammatory chemicals as used in injected vaccines, which can cause pain and swelling at the site of vaccination. It also produces cellular immunity that is not seen with intramuscular vaccination.

"Patients who lack cellular immunity can build up the needed antibodies to eradicate viral particles in the blood and interstitial fluid, but they may not be able to remove infected cells where the virus hides," said Baker. "This is often the case with chronically infected patients, so our vaccine may be of particular benefit to this population of immune-compromised individuals."

Robust immunity aside, the mucosal vaccine also eliminates a number of logistical impediments that have stymied traditional vaccine use worldwide: