Copycat. Viruslike particles mimic the structure of the norovirus to trigger a response of the immune system.
LigoCyte Pharmaceuticals Inc.
the next time a "stomach flu" you sprint to the bathroom, take heart: a vaccine could be on his path. Based on the results of a new clinical trial, the investigational vaccine is very effective against a strain of norovirus-bugs that may be responsible for over 0% of the collectively known digestive disorders such as gastroenteritis.
According to the Centers for Disease Control and Prevention (CDC) in Atlanta, noroviruses cause about 21 million cases of vomiting and diarrhea in the United States each year. In developing countries, infections cause about 0,000 deaths per year in children under 5 The virus is transmitted mainly through food, water or dirty hands that have been contaminated with the stool of an infected person . Norovirus is often called the "cruise ship virus" Outbreaks are common in confined living quarters, including military bases and hospitals Nursing homes are hot spots as well, the virus is a particular threat. for the elderly.
the development of a vaccine has been a research challenge. "noroviruses can not be grown in culture and do not infect laboratory animals," says clinical virologist Robert Atmar's Baylor College of Medicine in Houston, Texas. A breakthrough came in the early 190s, when Norwalk virus, a strain of norovirus, was cloned in the laboratory of molecular virology Mary Estes, also at Baylor. Estes found that when a certain key protein of the virus has been produced in cultured cells, the protein itself assembled 'particles' viruslike (VLPs) which may produce a strong immune response in laboratory animals. The discovery led LigoCyte Pharmaceuticals of Bozeman, Montana, to license and develop its own line of VLPs that mimic the structure near enough to wake up the immune system of the body against the virus of the virus but do not contain material that allows the virus to reproduce.
A vaccine VLP-greatly reduced both the rate of infection and the severity of symptoms, as shown by the clinical trial conducted by Atmar, Estes, researchers LigoCyte, and three other test centers. Ninety healthy volunteers received either the vaccine or placebo as a nasal spray in two doses three weeks apart. Participants were then admitted to one of four test hospitals, where they drank a powerful viral decoction and waited.
Approximately 80% of the placebo group was infected by the virus (as measured by the antibodies in their blood), but only about 60% of the vaccinated group did. He developed symptoms in 69% of the placebo group, but in only 37% of the vaccine group. The symptoms in the vaccinated group were also less severe and developed more slowly. (The 20%, uninfected subjects treated with placebo were probably immune to the previous exhibition, Atmar said.) The results of the test are presented today in The New England Journal of Medicine .
"This study is a proof of concept, the first to show that a vaccine can be effective against norovirus," Atmar said. Other studies, he said, are needed to monitor the success the vaccine in a home setting or a military base less controlled nurse, for example. Atmar added that if the vaccine protects against more than one strain of norovirus is still unknown. LigoCyte is conducting a trial of an injected form vaccine that works against two different types of virus.
virologist January Vinje CDC called the results encouraging news study. "it is a very safe vaccine as it does not contain viral genetic material," said -he. "A good next step would be to see if the vaccine generates enough of an immune response to provide protection in the elderly," he added, noting that the vast majority of outbreaks occur in long-term care facilities.
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