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Norovirus gets vaccine boost from plants

21 August 2009: Clinical testing on humans to start next year after vaccine to combat 'cruise ship' virus is developed in tobacco plants.

 

US researchers have used tobacco plants to help develop a potential new vaccine for the stomach bug norovirus, which causes sudden vomiting and diarrhoea.

Often called the ‘cruise ship virus’, the norovirus is highly contagious and can quickly spread through cruise ship liners, schools, hospital wings, care homes and offices. It is the most common cause of infectious gastroenteritis in England and Wales, and is responsible for an estimated 23 million bouts of the illness in the US.

The new vaccine was manufactured using plants rather than insect or animal cell cultures. The scientists generated the vaccine in a tobacco plant using an engineered plant virus.

Lead researcher Dr Charles Arntzen told the National Meeting of the American Chemical Society (ACS) that traditional manufacturing processes have been a barrier to generating vaccines for common illnesses like norovirus because they are always mutating. This can make them an extremely costly moving target for vaccine developers.

Plant biotechnology is a more efficient, cheaper way of producing vaccines. Dr Arntzen said: “With plant-based vaccines, we can generate the vaccine and do clinical tests within eight to ten weeks. This could easily be scaled up for commercial use in a two to four month period.”

To combat each new strain of norovirus and to keep up full resistance to older strains, Dr Arntzen said a booster of the vaccine could be given to people every 12 to 18 months.

So far the vaccine has only been tested in mice. Dr Arntzen hopes to start clinical trials in humans within the next year.

Dr Sneh Khemka, medical director for Bupa International said: “Although this research sounds promising, it doesn’t herald the end of the dreaded norovirus just yet. Until these findings have been published and clinical trials in humans completed, we won’t know how safe and effective it is.”

Key facts

  • Symptoms of norovirus include nausea and vomiting, as well as abdominal (tummy) cramps and diarrhoea
  • The illness is usually mild and most people make a full recovery after two to three days
  • There is no treatment for norovirus, but it is important to ensure you are drinking enough water to prevent dehydration, especially if you are elderly or very young
  • You can get norovirus at any age and more than once because immunity to the infection isn’t long-lasting
  • During outbreaks of norovirus, make sure you wash your hands regularly using soap and water, as well as thoroughly cleaning hard surfaces with bleach (especially in bathrooms)