A Nasal Hepatitis-B Vaccine Endows Robust Immunity

An innovative nasal hepatitis-B vaccine elicits a dramatic immune response in animals, without requiring a series of three vaccinations, sterile syringes, or refrigeration, claims a new study.

Researchers at the University of Michigan (Ann Arbor, MI, USA) and NanoBio Corportion (Ann Arbor, MI, USA) who are developing the nasal delivery vaccine have shown that a single dose triggered a protective response in animals roughly 450 times greater than that elicited by currently approved human vaccines. The vaccine is delivered directly to the mucosal lining of the nose, where immune cells recognize the foreign antigen contained in the vaccine; this produces three distinct types of immunity--mucosal, cellular, and systemic--which enable a rapid immune response not seen with intramuscular (IM) vaccination. This rapid stimulation of the immune system does not involve inflammatory chemicals as used in IM vaccines, which can cause pain and swelling at the site of vaccination.

The vaccine is safe and simple to produce, with a nanoemulsion that contains a mixture of oil, water, alcohol, and two surfactants, together with commercially available antigens. The nanoemulsion itself also serves as the adjuvant to stimulate an immune response, demonstrating significant antigen-sparing properties. The formulation is extremely stable, allowing for long-term storage of three to six weeks or longer with potentially no refrigeration.

A single-dose administration schedule incurs rapid immunity, whereas traditional injected vaccines usually require as many as three separate vaccinations over 6 months. The study was published early online in the August 13, 2008, issue of the journal Public Library of Science (PLoS) One.

"We have developed a new vaccine that is extremely safe, easy to administer, and which rapidly builds protection against hepatitis-B infection,” said lead author James R. Baker Jr., M.D., founder of NanoBio. "The same vaccine platform has also been shown to elicit significant immune responses in animal studies with influenza, anthrax, smallpox, RSV [Respiratory syncytial virus] and HIV. Plans are under way to begin testing in humans.”

Developing nations have difficulty providing proper refrigeration, sterile needles, or three separate vaccinations (as are currently required), three factors that impede the delivery of existing hepatitis-B vaccines. 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.

Related Links:
University of Michigan
NanoBio Corportion