The H in H1N1 stands for hemagglutinin, the virus’s outer protein and one that human immune systems respond to. There are 15 known versions of the protein, only five of which are specific to human disease. So by targeting these hemagglutinin proteins, Inovio’s system should, at least in theory, be effective not just for seasonal flu, but for avian (H5N1) and swine (H1N1) flu as well. “There’s nothing magical about swine H1N1 versus seasonal flu,” Kim says. “It’s just a divergence from what your body has been exposed to, and looks different enough to the immune system to evade it.”
In animal tests, this certainly seems to be the case. The company has tested the H1 component of the vaccine in mice infected with the virulent, epidemic-causing 1918 version of the H1N1 virus. The vaccine prevented any visible symptoms in inoculated mice, while every single one of the nonvaccinated mice died.
Of course, putting something as novel as an electroporation vaccine into widespread use could prove difficult especially because it requires its own technology, which is currently expensive. “If you have to do electroporation, that could potentially be a difficult thing to implement, certainly more difficult than spraying something up someone’s nose,” says Greg Poland, director of the Mayo Clinic’s Vaccine Research Group, in Rochester, MN. (This is how live, weakened-virus flu vaccines are currently administered; inactivated-virus vaccines are given with the classic needle and syringe.)
As far as the vaccine itself goes, most of the experts are in agreement. “The idea is a very good one, the need is a great one, and any company that would make a dent into this would certainly be a winner,” says virologist Peter Palese, head of the microbiology department at Mount Sinai School of Medicine, in New York City. But, although the company’s animal studies are an improvement over earlier DNA vaccination results, he notes that “the proof of the pudding will lie in human trials.”
Inovio has tested its H1 and H5 components in animals, and the group hopes to start human trials of the H5 component in early 2010. H1 tests, they believe, are just a short distance behind. “We think it would likely take two shots, a month apart, and then a booster every five years,” Kim says.
Inovio isn’t limiting itself to influenza, either. It has an HIV vaccine in development and is also working to create vaccines for diseases that are of greater concern in developing countries: malaria and dengue are at the top of the list. In contrast to the $20 billion flu-vaccine market, though, “such vaccines hold promise but will never even start to pay for themselves,” says Scripps’s Tom Edgington. “It’s a long path to something that helps the public and changes the world.”