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This vaccine specialist is attempting to create a product that will protect people from influenza A for every future flu season without re-formulation. They are thinking about how to fight influenza B, too.
A collaboration between Acambis PLC and the Flanders Interuniversity Institute for Biotechnology aims to develop a “universal” influenza vaccine, which would not have to be altered each year.
Every year the FDA Vaccines and Related Biological Products Advisory Committee meets to decide what strains of the influenza virus should be included in the vaccine for the following autumn, Center for Biologics Evaluation spokesman Paul Richards said. The committee contains representatives from, the Centers for Disease Control, the World Health Organization and the Department of Defense.
There are two main strains of influenza, A and B, according to CDC. Both are continually mutating, so it is necessary to have a new vaccine every flu season, Richards said. Production takes about six months.
This creates a problem, according to Paul Glezen of the Baylor College of Medicine, because new variants often do not surface until after the vaccine is set.
If a “universal” vaccine were developed, it would eliminate this difficulty.
Richards noted that the FDA has historically supported research into a vaccine that could protect people for more than one year. If the science can support a “universal” solution, it could “cure, mitigate or prevent” influenza, according to a statement Dr. Jesse Goodman, CBER director.
If a person is vaccinated, they are exposed to a harmless version of virus, including the particular surface proteins specific to that strain, Glezen explained. The person will develop antibodies bind to these surface proteins and prevent them from binding to their targets and allowing the infection to take hold.
Influenza A is the most frequently pandemic strain, said Richard Weltzin, senior director of viral immunology at Acambis. This is because the virus mutates most rapidly, according to CDC. Most influenza A viruses target one of two receptor proteins, Glezen said. Hemigglutinin attaches to cells in the lungs and neuraminidase helps the infection progress.
But Acambis is working on a virus that targets a protein called M2e, Weltzin said. This is a channel that allows charged molecules to flow into the interior of the virus and make it acidic.
Its role is not completely understood, according to Weltzin. But it does not elicit much of an immune response from the body. As a result there are not antibodies that attach to it and it does not mutate very often.
So Acambis is trying to enhance the immune response to M2e by attaching a particulate carrier protein to a virus-like particle that will enhance the reaction to M2e. The drug amantadine, which is sometimes used to treat influenza A, works on the M2e receptor, Weltzin said.
Acambis acquired the influenza A vaccine technology from Apovia, which licensed it from the Flanders Interuniversity Institute for Biotechnology.
It is working with the university to discover a target protein for influenza B that is similar to M2e, Weltzin said.