Joanna Kirman

The head of the Wellington-based Malaghan Institute's infectious diseases research programme Dr Joanna Kirman has developed a novel strategy of trapping immune cells at specific sites in the body and then checking how this affects the ability of the immune system to protect against TB.

Her team has been able to show that following vaccination against the disease, it is immune cells right at the site of infection in the lungs that play an essential role in controlling the growth of TB bacteria in the early stages of disease.

"Our research suggests that a vaccine needs to drive the protective cells to the lung if we want to achieve good protection against TB," Dr Kirman says.

The team has just had its work published in the European Journal of Immunology.

The research will help a strong international effort to develop an effective vaccine for the disease that kills more people worldwide than any other bacterial disease.

When TB attacks the lungs, it usually leads to a persistent cough, night sweats and weight loss. It is spread through coughs or sneezes, and is often found in crowded and poor households.

TB can take months or even years to show symptoms. A "new" case of tuberculosis in a year 13 student coughing blood at Palmerston North Boys' High School in June was apparently linked to a major outbreak of the disease which hit the school in 2006, when 250 of the 1,800 students and staff at the college were infected.

Dr Kirman says vaccines have only limited reliability, and that drug-resistant strains of the disease are spreading internationally, so there is an increasing need for more effective vaccines.

"Our struggle to develop a more effective vaccine has stemmed in part from a poor understanding of the immune mechanisms that orchestrate protection against TB," she said.

"If we can identify the critical players, and the factors that contribute to their protective nature, then we are far better placed to develop a better TB vaccine."