New TB vaccine trial in Africa3rd August 2007
Researchers in the Gambia and South Africa have begun clinical trials of a new vaccine for tuberculosis, according to the UK-based body which is funding the research.
The Wellcome Trust is backing the MVA85A vaccine, which may provide a new line of defence against TB, especially among those who are also living with HIV.
Developed at the University of Oxford, the vaccine is designed to be used alongside existing immunisations.
It uses a protein from the Mycobacterium tuberculosis microorganism which causes TB to stimulate an immune response by activating T cells. It can also boost the effect of the existing Bacille Calmette-Guerin (BCG) vaccination.
BCG still offers protection against severe forms of the disease, but the effect can wear off as children approach adulthood, researchers say.
It is also not safe for people with AIDS, and possibly not those living with HIV either.
Tony Hawkridge, senior clinical researcher at the South African Tuberculosis Vaccine Initiative at the University of Cape Town said this was because it is a live vaccine that can cause disease in people with weak immune systems.
Lead researcher on the vaccine development team Helen McShane, a Wellcome Trust senior clinical research fellow, said that data from HIV negative adults and adolescents in South Africa had shown that the new vaccine was safe, and that it generated very strong immune responses.
A phase II clinical trial has already begun on infants in the Gambia.
Researchers will study data from 471 HIV-negative four-month-old babies to determine the level of immune response it triggers at particular dosing levels and how it interacts with other vaccinations, such as those for diphtheria, pertussis (whooping cough), tetanus and Haemophilus influenzae type b (Hib), which causes pneumonia and meningitis.
South African researchers are also conducting trials with HIV positive adults, as one third of the world's HIV positive population also has TB.
Jerald Sadoff, chief executive officer of the Aeras Global TB Vaccine Foundation, said HIV/AIDS and TB were all too often found in the same patients and the same communities. He said both were diseases of poverty, with each making the other worse.
He said a new vaccine was crucial if efforts to eliminate TB were to succeed. He estimated that a million to a million and a half lives could be saved annually if better diagnostics and antibiotics were available.
Around one and a half million people die every year from TB. 98% of them are from the world's poorest countries.
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Title: New TB vaccine trial in Africa
Author: Luisetta Mudie
Article Id: 3620
Date Added: 3rd Aug 2007