Vaccine hope for travel diarrhoea

Main Category: Public Health
Article Date: 14 Aug 2003 - 0:00 PDT

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Holidaymakers could soon be able to take a single pill to stop them from having tummy trouble when they go abroad.

Microscience, a Berkshire company, has started testing a potential vaccine for diarrhoea.

Laboratory tests have shown that it can protect against enterotoxigenic E. coli (ETEC), a bacterium which causes most cases of travellers' diarrhoea.

The vaccine could be of major benefit to people who visit Africa, South-East Asia and the Indian sub-continent, Central and South America and the Caribbean.

Over half of people who travel to countries in those regions suffer at least one bout of diarrhoea during their stay.

However, experts say it is unlikely to benefit people living in these countries because it protects against just one of many pathogens that can cause diarrhoea.

Single dose

A vaccine for this type of diarrhoea already exists. However, it is not yet licensed in the UK and people need to take two doses to gain protection.

This latest vaccine is effective in just one dose, according to the scientists behind it.

While the vaccine is currently given in liquid form, it could be made available in pill form in the future.

Phase one clinical trials of the vaccine involving over 30 volunteers is now underway.

If the vaccine proves safe, it will then be tested on more people including those living in developing countries.

'We are evaluating the safety of the vaccine in healthy subjects now,' Dr Steve Chatfield of Microscience told BBC News Online.

'We will also look to make sure that we are getting a response. If that is successful we will take it into phase two and phase three clinical trials, to test its efficacy.

'Eventually, we will go to developing countries and test it there.'

But he added: 'It will be several years before the vaccine will be licensed. These are early clinical studies.'

This vaccine may protect against what is known as acute watery diarrhoea.

This can last for up to 14 days and can include vomiting and fever. It causes dehydration, which if left untreated can cause death.

This type of diarrhoea is common throughout much of the developing world.

Demand from travellers

Dr Ron Behrens, an infectious disease expert at the London School of Hygiene and Tropical Medicine, said many travellers could benefit from the vaccine if it proves to be effective.

'I think there could be a demand for this vaccine if it is effective in a single dose and if it is cheap.

'Between 50% and 60% of people who travel to the tropics suffer from diarrhoea.'

However, he said the vaccine was unlikely to be of benefit to people living in developing countries.

'There are probably thousands of different pathogens that cause diarrhoea. I would be really surprised if this vaccine did have a role in the developing world.'

Carolyn Driver, chairwoman of the British Travel Health Association, said a vaccine could help many travellers.

'Diarrhoea is the number one cause of ill-health among travellers to developing countries,' she said.

'Anything that looks like it may cut down on this is good news. If this is effective and if it can be taken in one dose, it will certainly be looked at with interest.'