Virus-mimicking nanoparticles can stimulate long-lasting immunity

Vaccine scientists say their “Holy Grail” is to stimulate immunity that lasts for a lifetime. Live viral vaccines such as the smallpox or yellow fever vaccines provide immune protection that lasts several decades, but despite their success, scientists have remained in the dark as to how they induce such long lasting immunity. Scientists at the Emory Vaccine Center have designed tiny nanoparticles that resemble viruses in size and immunological composition and that induce lifelong immunity in mice. They designed the particles to mimic the immune‑stimulating effects of one of the most successful vaccines ever developed — the yellow fever vaccine. The particles, made of biodegradable polymers, have components that activate two different parts of the innate immune system and can be used interchangeably with material from many different bacteria or viruses. The results are described in this week’s issue of Nature. “These results address a long‑standing puzzle in vaccinology: how do successful vaccines...