Oral flu vaccine under development
LEIPZIG, Germany: Dentists may soon be able to vaccinate patients against the flu and other illnesses. Researcher Song Joo-Hye and her colleagues at the International Vaccine Institute (IVI) in Seoul have found that sublingual administration of an experimental flu vaccine is highly effective in protecting mice from influenza virus infection. When the flu vaccine was applied under the tongue, the animals developed robust immune responses in their lungs and were fully protected from the disease when later exposed to a more severe form of the influenza virus.
The study is based on a earlier study, conducted by the IVI in collaboration with the National Institute for Health and Medical Research in France and Gothenburg University in Sweden. In addition to offering a convenient and safe way to deliver vaccines without needles, scientists in the study found the sublingual route helps to overcome the degradation of antigens during their transit through the gastrointestinal tract and failed to induce strong immune responses in the respiratory tract—the two main drawbacks of orally administered vaccines.
“Moreover, the findings suggested that this method of vaccine administration poses no risk of antigen redirection to the central nervous system, which is a potential risk of administering influenza vaccines intranasally,” added Dr Kweon Mi-Na, chief of the IVI’s mucosal immunology laboratory.
“These studies provide a basis for further human testing of this alternative form of needle-free vaccination,” said Dr. Cecil Czerkinsky, IVI Deputy Director-General for Laboratory Science. “Aside from its convenience, sublingual vaccination appears to disseminate immunity to a broader range of organs than the classical routes of injecting or ingesting vaccines.” If these findings are replicated in humans, they could pave the way for the development of a new generation of vaccines that could be used for mass vaccination against respiratory infections, including the pandemic avian-human influenza viruses.
Dr John Clemens, IVI Director-General said: “These studies are important milestones for the IVI. Sublingual vaccination is an entirely new approach to the delivery of vaccines; this approach offers the possibility of vaccinating against a variety of infections without the risks posed by delivering vaccines with needles.”