Call it what you like--stomach flu, gastroenteritis, tummy bug, winter vomiting virus--norovirus infections are not fun, especially on a cruise ship, and are even worse in a hospital ward. In the future, a simple nasal spray could be all that's needed to protect from a nasty bout of sickness.
The vaccine is sprayed up the nose, and is based on norovirus proteins produced in genetically engineered tobacco plants. These form virus-like particles or VLPs that look like empty noroviruses, and do not cause infection. The particles are then mixed into a powdery carrier that sticks to the inside of the nose and triggers an immune response in the mucous membranes, and this response is mirrored in the mucous membranes in the rest of the body, including the gut. Because the bug goes for the cells in the top layer of the gut, a traditional shot--which builds up antibodies in the blood--may be less likely to work. Using a nasal version appears to be more effective than an oral version, perhaps because it avoids being broken up in the gut.
According to the U.K. Telegraph, professor Charles Arntzen of Arizona State University said, at the American Association for the Advancement of Science (AAAS) annual meeting in Vancouver: "The technical issues are probably solved, now it is regulatory issues. If everything went well and there was enough financial support we could have a vaccine in four to five years."
The potential vaccine, which has so far only been tested in animals, cuts symptoms in about 50% of cases but does not get rid of them completely. To be really useful, it will have to work in more people, perhaps include proteins from more strains of the virus, and will have to go through the full range of human trials. The vaccine's protection could last for up to two years.
The highly infectious norovirus causes vomiting and diarrhea, and could be responsible for up to 90 percent of all non-bacterial epidemics of gastroenteritis. Only a few copies of the virus are needed for infection; the viruses can "live" in the environment for days or even weeks, and even once people have recovered they can still be infectious for up to a month. A bout of stomach flu in a healthy person is just rough for a few days, but in young children and the elderly could be dangerous.
The vaccine, once it has gone through human trials, could be used to protect staff and vulnerable people in hospitals and nursing and care homes, or even be added into the plethora of traveler's shots needed before a trip abroad.