There is still a long way to go before products, which would fight bacteria, as a 'vaccine' are widely available

BDA spokesman

It also helps form plaque, which then attacks the teeth.

The British vaccine developed by Dr Julian Ma and colleagues at Guy's hospital in London consists of highly purified antibodies, that attack the bacteria.

But unlike most inoculations, the vaccine does not trigger an immune response and the scientists fear it might have to be repeated every couple of years.

Dr Ma said the London team was ready to start clinical trials, but admitted progress could be slow because of the time it takes tooth decay to become noticeable.

He said: "Unlike most other illnesses, caries take a few years to develop."

Future hope

The American scientists Drs Martin Tauban and Daniel Smith, from the Forsyth Institute, in Boston hope their vaccine, which is given nasally, could bring a life-long protection.

They say it will be most useful for children aged from 18 months to three years.

Their vaccine aims to target the enzyme which creates the plaque which clings to teeth.

If they can do that they say people should be able to brush off the bacteria when they brush their teeth.

Adults were given an oral version of the vaccine and it found they produced anti-bodies to the bacteria.

Brushing still needed

A spokesman for the British Dental Association (BDA) said people should remember that a vaccine would be some way in the future.

"Although this research represents good news for anyone with an interest in fighting tooth decay, there is still a long way to go before products, which would fight bacteria as a vaccine are widely available.

"Indeed, the BDA believes that despite these developments people should not forget the more basic ways of maintaining healthy teeth including brushing your teeth twice a day with a fluoride tooth paste and visiting their local dentist."

The study appeared in New Scientist.