9 August 2002

Little vaccine hope

DESPITE being four years into a 15 year research project, scientists at the Institute of Animal Health, Compton, say there is little hope of a TB vaccine being developed in the next few years.

"We are at the very early stages of the research programme and are carrying out fundamental work on the micro-bacteria," says Geoffrey Oldham, scientific assistant to the director at IAH.

Work underway at Compton is centred on understanding the fundamental biology of the Tuberculin micro-bacteria to develop a vaccine.

"The greatest challenge facing researchers is that the Tuberculin bacteria is able to survive in the host organism where other bacteria cant survive. While we have isolated the bacteria and sequenced the genome, we cant yet identify which molecule the host reacts to," says Dr Oldham.

A bacteria has thousands of individual molecules and it appears that only one of these molecules reacts with the host organism to cause a TB infection, finding which one is the most difficult part of developing the vaccine.

Vaccine development has also troubled scientists working with human TB. While the BCG vaccine is successful in the UK, it is not in other parts of the world. This is something which IAH researchers are having to bear in mind while developing a cattle vaccine, according to Dr Oldham.

"The fact that the BCG vaccine works in one part of the world and not another is of concern to us, as it means that the same could also be true of a cattle TB vaccine." &#42