Vaccine that could spare millions the misery and indignity of the winter vomiting bug could be available in just four years
A vaccine that could spare millions the misery and indignity of the winter vomiting bug could be available in just four years.
The drug, a powder which is puffed up the nose, is likely to be popular with business people who travel a lot and can’t afford to lose time due to sickness.
Norovirus thrives in cramped conditions and so the vaccine could also benefit children in nurseries, elderly people in care homes and patients going into hospital.
Highly contagious: The norovirus can spread rapidly, particularly in confined spaces
The virus’s reputation for causing outbreaks in the confines of cruise ships and army barracks might also make it popular with holidaymakers and the military.
The most common cause of stomach bugs, norovirus is up to 100,000 times more infectious than salmonella – but there is no treatment, other than staying warm indoors and drinking plenty of liquids.
But hope is in sight with two nasal vaccines being developed in the U.S.
The American Association for the Advancement of Science’s annual conference today heard details of one of these drugs.
The vaccine, which produces a ‘wonderful’ immune response in animals in the lab, is being developed by a consortium of companies headed by experts at Arizona State University.
The powder, which is puffed up the nose, contains a man-made version of the virus’s outer shell, which tricks the immune system into providing protection against the disease.
It is produced in massive quantities in the leaves of tobacco plants, with 2lbs of leaves greenery producing 10,000 doses of vaccine.
The inclusion of an extract of aloe vera
helps the powder stick to the inside of the nose long enough for an
immune response to kick in.
WHAT IS NOROVIRUS
‘Norovirus’ is the collective name given to a highly contagious group of viruses which cause vomiting and diarrhoea, particularly during the winter months. Indeed, norovirus is sometimes called ‘winter vomiting bug’, as outbreaks are always worst from October to March.
The norovirus is highly infectious – you need to be exposed to only 10 to 100 virus particles to catch it, whereas to catch the seasonal flu virus you’d need to be exposed to around 10,000 particles.
The main symptom is a sudden onset of nausea and projectile vomiting. There will also be watery diarrhoea, but this will not be as urgent or as bad as the vomiting.
Many people also experience stomach cramps and some will develop flu-like symptoms such as a temperature, aching limbs and general weakness.
The immune system of the nose and stomach are linked, and should someone later be exposed to the real virus, their stomach will mount a defence against the infection.
Arizona State University’s Professor Charles Arntzen said the vaccine is still in the early stages of development. But it is thought that one to two doses of the powder will have to be taken initially.
Booster shots, in which a single dose is puffed up the nostril, will be necessary every six months to two years.
The price is still to be decided but it is likely to cost around 30 a shot. In contrast, the flu jab costs around 12 a shot and the rabies travel vaccine, 50.
The second vaccine is being developed by Montana firm Ligocyte Pharmaceuticals.
Professor Arntzen estimates the drugs are four to five years from the market with businesspeople who don’t want to get sick being among those keenest to take it.
He also envisages that some nurseries may insist that children are given the vaccine.
With some military operations being delayed by the bug, it could also become routinely used in the armed forces.
There have been 755 outbreaks of norovirus in hospitals since last June and 520 of these led to admissions to wards being stopped or restricted.
At its peak, it claims 200,000 victims a week and costs the economy 40million a day in lost productivity.