Irish Times (10.16.12)
Oxford-based scientists have called for more and better vaccines ahead of the publication of new World Health Organization statistics on the rising incidence of tuberculosis (TB). Bacille Calmette-Guérin (BCG) was the first vaccine used against TB beginning in 1921. It is still the only vaccine in use against a disease that kills nearly 1.5 million people each year. TB is becoming increasingly resistant to the drugs that now combat it.
After World War II, BCG saved millions of lives in Eastern Europe after eight million children were vaccinated; thus, the much-feared epidemic of TB was controlled by widespread vaccination. Though effective in preventing tuberculous meningitis in infants, BCG has a much worse record fighting off pulmonary TB, especially in adolescents and adults, scientists in London said October 15.
Professor Helen McShane, Oxford University Professor of Vaccinology, has developed a vaccine of great promise called MVA85A. It is the first new TB vaccine to have begun clinical trials since BCG did so 81 years ago. Work on MVA85A has been under way for more than 10 years. In the spring of 2013, Professor McShane and her team will learn the results of the first efficacy trial in South Africa—where half of the babies chosen were given the vaccine, and the other half received a placebo. The MVA85A vaccine will attempt to improve the effectiveness of BCG, not replace it. However, the team still does not know what responses it must provoke in a patient’s immune system to ensure that TB can be held at bay, explained McShane at a Wellcome Trust briefing.
There have been no new TB drugs for more than 50 years, notes the United Kingdom’s Parliamentary Office for Science and Technology. Today, 10 drugs—as distinct from vaccines—are in clinical trials. Bedaquiline, one of these drugs, has already been cleared for use on patients with drug-resistant TB. AIDS and HIV patients are particularly at risk and make up nearly one in seven of all TB cases worldwide. They are 21 to 34 times more likely to develop infection from the mycobacterium that causes TB.