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So. Africa: Deadly Tuberculosis Faces New Weapon as Vaccine Enters Tests

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  • So. Africa: Deadly Tuberculosis Faces New Weapon as Vaccine Enters Tests


    Deadly Tuberculosis Faces New Weapon as Vaccine Enters Tests

    By Kanoko Matsuyama and Jason Gale

    March 23 (Bloomberg) -- Scientists will start the largest study in almost a century on a new vaccine against tuberculosis, attempting to improve on an existing immunization that only partially protects against the deadliest bacterial illness.

    The research will gauge the shot?s ability to prevent the lung disease in a trial starting next month involving 2,800 babies in South Africa, said Jerald Sadoff, head of Aeras Global TB Vaccine Foundation, which is co-sponsoring the study. The Rockville, Maryland-based group is trying to develop a successor to the Bacillus Calmette-Gu?rin vaccine, or BCG, which has been used in humans since 1921 and doesn?t prevent infants from developing TB of the lungs, where the bacteria first takes hold.

    Tuberculosis has plagued man since prehistoric times. It infects about 8.8 million people and kills 1.7 million each year, according to the World Health Organization. Medicines used to battle the bacterium are increasingly failing because the airborne bug has mutated, spawning strains that aren?t defeated by even the most powerful antibacterial drugs.

    ?A vaccine is absolutely essential if we are going to get this epidemic under control,? said Sadoff, who led efforts to develop eight vaccines at Merck & Co., where he was head of clinical development for three years.

    Aeras, which is supported by the Bill & Melinda Gates Foundation, is developing the most advanced experimental vaccine with an Oxford University venture, the Oxford-Emergent Tuberculosis Consortium.

    Crucell Shot

    Next month?s trial will assess ?proof of principle? of the vaccine as part of the second of three stages of patient studies usually required by the U.S. Food and Drug Administration and other regulators. Tests on a product developed with Crucell NV of the Netherlands may start two months later, Sadoff said in a March 20 telephone interview.

    Aeras, which has four other candidates in earlier stages of patient studies, wants regulatory approval for at least one TB shot by 2014, said Sadoff. Using vaccines to help the body fight TB is key to curbing drug-resistant strains, according to Marcos Espinal, executive secretary of the Geneva-based WHO?s Stop TB Partnership.

    ?This is an absolutely pivotal trial,? said Helen McShane, an HIV physician and researcher at Oxford, who created the most advanced experimental vaccine as a Ph.D. student in 1999. McShane incorporated a tuberculosis protein into a genetically manipulated smallpox vaccine to train the immune system to recognize and attack TB.

    Finding Babies

    Scientists will test McShane?s shot on infants at the Brewelskloof TB hospital in Worcester, South Africa, 120 kilometers (75 miles) north of Cape Town. The recruitment of babies will begin in early April, she said in an interview. All babies will be immunized with the BCG vaccine at birth. Half will receive the experimental vaccine at 18 weeks of age, while the rest will be given a dummy shot.

    The study aims to show at least a 60 percent reduction in TB of the lungs among children given the experimental vaccine compared with those who got the placebo. Initial results may be available around 2011 or 2012, McShane said.

    The BCG is given to about 100 million babies at birth each year, mostly in developing countries where there is high prevalence of the disease in the community. In infants, the shot helps prevent the most serious forms of tuberculosis, such as TB meningitis, which is often fatal.

    McShane?s shot aims to stop tuberculosis developing in the respiratory system, where it enters the body in the form of microscopic bacteria carried in the air.

    Worse in Africa

    ?This is the first of the new-generation TB vaccines to go into this kind of study looking at efficacy in infants,? she said. ?It?s enormously exciting and I sincerely hope we will see some efficacy.?

    The study, which will cost an estimated $14 million, is a collaborative effort with the South African Tuberculosis Vaccine Initiative and is funded by Aeras and the Wellcome Trust, the U.K.?s largest charity.

    TB mortality rates are more than four times higher in Africa than elsewhere in the world, according to the WHO. More than 1.5 million new cases occur annually in Sub-Saharan Africa, the region accounting for a third of new cases of HIV, the AIDS -causing virus, worldwide each year. The human immunodeficiency virus attacks the body?s T-cells, the immune defenders that normally help keep pathogens such as tuberculosis at bay.

    Coughing, Weight Loss

    About 2 billion people worldwide are infected with tuberculosis, and most are in the early, or latent, stage of the potentially lethal disease, before coughing, weight loss and fevers begin. While it usually affects the lungs, tuberculosis can attack almost any organ or tissue in the body, including the brain, liver, and bones.

    Each year about 40,000 people worldwide develop extensively drug-resistant TB, or XDR, a strain that doesn?t respond to doctors? first treatment choices. Drug resistance makes TB more dangerous and treatment more expensive. Since 2006, 55 countries have reported at least one XDR-TB case.

    The cost of hospitalization, surgery and treatment with stronger drugs, such as Eli Lilly & Co.?s Capastat, can reach as much as $500,000 for each case in the U.S. That?s 100 times more than with first-line therapies. At least half of patients with XDR tuberculosis die.

    To contact the reporters on this story: Kanoko Matsuyama in Tokyo at; Jason Gale in Singapore at