Nanoparticle-Based Vaccine Shows Broader, More Potent Flu Immunity
Scientists at the National Institute of Allergy and Infectious Diseases’ Vaccine Research Center today report on their generation of a self-assembling nanoparticle vaccine, which they say shows broader and more potent immunity than traditional influenza vaccines.
Writing in Nature, lead author Gary J. Nabel, Ph.D., and his colleagues describe their approach and show that “antibodies elicited by a 1999 haemagglutinin-nanoparticle vaccine neutralized H1N1 viruses from 1934 to 2007 and protected ferrets from an unmatched 2007 H1N1 virus challenge,” they write. (Dr. Nabel is currently svp, CSO, and deputy to the president of R&D at Sanofi, which produces commercial flu vaccines.)
The researchers genetically fused haemagglutinin to ferritin, a protein that naturally forms nanoparticles comprised of 24 identical polypeptides, in such a way that the former protein spontaneously assembled and generated eight trimeric viral spikes on its surface.
“This structure-based, self-assembling synthetic nanoparticle vaccine improves the potency and breadth of influenza virus immunity, and it provides a foundation for building broader vaccine protection against emerging influenza viruses and other pathogens,” the authors add.
An NIH Office of Technology Transfer (OTT) document dated July 2012 elaborates on the clinical utilities of the Vaccine Research Center team’s approach, saying: “This technology exploits ferritin, a ubiquitous iron storage protein, that self-assembles into spherical nanoparticles and could serve as a scaffold to express a heterologous protein, such as influenza HA, so it mimics a physiologically relevant trimeric viral spike.”
The OTT adds that these HA-ferritin nanoparticles can be produced from simple expression vectors, eliminating the need for the production of infectious virus in eggs—a comparatively costly and time-consuming process.
The study, “Self-assembling influenza nanoparticle vaccines elicit broadly neutralizing H1N1 antibodies,” appeared online in Nature May 22.