New Zika Vaccine Candidate
A new Zika vaccine candidate has the potential to protect against the virus with a single dose, according to a research team led by scientists from the Perelman School of Medicine at the University of Pennsylvania. As reported in Nature this week, preclinical tests showed promising immune responses in both mice and monkeys.
"We observed rapid and durable protective immunity without adverse events, and so we think this candidate vaccine represents a promising strategy for the global fight against Zika virus," said senior author Drew Weissman, MD, PhD, a professor of Infectious Disease at Penn. "We hope to start clinical trials in 12 to 18 months."
The research involved a collaboration among Weissman's laboratory at Penn and several others, including the laboratories of Barton F. Haynes at Duke University and Theodore C. Pierson at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH).
Prompted by the recent Zika virus outbreaks in Latin America and some parts of the United States, scientists around the world have been racing to develop candidate vaccines, and already several have been tested in animals. The new candidate vaccine is the first to show such potent and long-lasting protection without the use of a live virus.
Asteroid Myth Busted
Some 470 million years ago, during the middle part of the geological period known as the Ordovician, an asteroid collision took place somewhere between Mars and Jupiter. The collision caused an explosion that sent a cascade of meteorites towards Earth. The heavy bombardment on Earth continued for millions of years, and even today some 20% of all meteorites that reach Earth originate from this asteroid break-up. At the same time, Earth witnessed the greatest rise in marine biodiversity since the origin of multicellular life. So, the question is: was there a connection between these two fundamental events in Earth history, as has been proposed? A new study now demonstrates that the rise in biodiversity commenced long before the asteroid collision.
The link between these two fundamental events -- the so-called Ordovician radiation and the sustained meteorite bombardment -- has, for many years, presented a paradox in science. We are used to hearing the story of meteorite impacts that leads to the loss of species richness, such as when the dinosaurs went extinct 65 million years ago. But could the opposite scenario be a possibility as well? asks Assistant Professor Christian M. Ø. Rasmussen from the Natural History Museum of Denmark rhetorically. He is co-authoring the study in which an incidental finding of the rare mineral zircon within the meteorite-bearing rock layers led to an answer to the paradox.