The search for an effective vaccine to combat tuberculosis is gaining momentum, with the first human trials in sub-Saharan Africa scheduled to begin in October in Worcester.
Greg Hussey, a professor in the paediatrics department at the University of Cape Town, told a medical conference in the city yesterday that finding a safe and effective vaccine against TB was a global emergency because of the high rate of infection, the resistance of the disease to the drugs
used to treat it and the impact of HIV/AIDS. About 50% of TB patients in South Africa were HIV-positive, he said.
More than 500 health professionals attended the combined paediatrics and allergy conference at the Cape Town International Convention Centre. The announcement of the phase one trial in Worcester follows a plea by Nelson Mandela at the recent Bangkok AIDS Conference for world leaders not to ignore TB.
Hussey said that while the Baccillus Calmette-Guerin (BCG) vaccine - administered since the 60s in South Africa - protected children from severe disease like TB meningitis, it was not effective against pulmonary TB, a more common form of the disease.
The BCG vaccine was also not effective in adult pulmonary TB and the immune response to the vaccine depended on the patient's nutrition. The safety of BCG vaccine in HIV-positive children was also questionable.
Hussey said that for the Phase One trial the BCG vaccine had been turbo-charged to make it more effective. This involved extracting a part of the BCG vaccine that has an immune response to TB, making it stronger and reinserting that part into the BCG vaccine, Hussey said.
About 50 adults will take part and if subsequent trials are successful, an effective vaccine could be on the market by 2010.
Earlier, Hussey called on delegates to consider launching a vaccination action campaign to fight for affordable, safe and efficacious vaccines.
He said it could be modelled on the Treatment Action Campaign, which had been successful in lobbying for the introduction of antiretroviral treatment.
Hussey was responding to a talk by Shabir Madhi, of the University of the Witwatersrand, who has tested a new pneumococcal vaccine, which has proved effective in reducing pneumonia in children, including those who are HIV-positive.
However, Madhi said the vaccine was unaffordable, putting it out of reach of children in need. Vaccines for chicken pox, hepatitis C and influenza were also too expensive. British professor Robert Aston said vaccination was probably the most outstanding medical science intervention.
Vaccines had done more than anything else to reduce the human burden of suffering and premature death, especially among children, he said. Glenda Grey of the Perinatal HIV Research Unit at Chris Hani-Baragwanath Hospital said major challenges facing vaccine research included setting up trials for adolescents who are most at risk of contracting HIV/AIDS and finding a vaccine to reduce the transmission of HIV through breast milk. (Source: The Cape Times, 17 August 2004)