Tuberculosis experts pin hopes of controlling disease on 12 vaccines in developmentBMJ 2012; 345 doi: http://dx.doi.org/10.1136/bmj.e6981 (Published 16 October 2012) Cite this as: BMJ 2012;345:e6981
The advent of more effective vaccines against tuberculosis is an increasingly realistic possibility, say public health experts with an interest in the illness. Tuberculosis is currently the world’s second deadliest infection, with 8.8 million new cases in 2010.
“In the last decade we’ve gone from having no vaccines in development to now having 12 different candidates at various stages in the clinic and in human trials,” said Ann Ginsberg, vice president of scientific affairs for Aeras, a foundation devoted to the development of vaccines against tuberculosis.
Increasingly concerned over the rise of drug resistant tuberculosis, she and others in the field have long insisted that success in tackling the resurgence of the illness will depend on access to a better vaccine.
What changed the outlook, said Ginsberg, was an influx of funds in the 1990s from various governmental and charitable sources. “A lot of bright young scientists then came into the field, and new discoveries were made. But to convert these into new tools that we can use to control the disease has only started to happen in the last 10 years,” she said.
The vaccine at the most advanced stage of testing, called MVA85A, has been developed by Helen McShane, professor of vaccinology at the University of Oxford.
“It’s a vaccine that’s designed to boost the effects of BCG,” she explained. BCG itself, although still the world’s most widely delivered vaccine, is unreliable, especially in adolescents and adults.
“Since 2002 we’ve conducted many clinical trials on MVA85A, first in the UK and then across Africa, looking at safety and immunogenicity in different populations who most need it, particularly babies, HIV infected adults, and adolescents,” said McShane.
The first efficacy data on MVA85A should be available early in 2013. “We have about 3000 babies, all of whom received BCG at birth,” said McShane. Half then received MVA85A as well and half received placebo. By the time the findings are available, she and her colleagues will have followed them up for two years.
McShane and Ginsberg were speaking at a briefing held by the Science Media Centre in London to review not only recent achievements in tuberculosis control but also continuing obstacles. Among the obstacles is uncertainty over which of the animal models used by researchers is the best predictor of vaccine efficacy in humans.
Another speaker at the meeting was Tim McHugh, professor of medical microbiology at University College London. Referring to the treatment of tuberculosis, he pointed out that, although effective, treatment depends on four complex drugs that may cause side effects. “People often stop taking them when they feel better, or they don’t take the full course. And this leads to drug resistance,” he said.
“For a long time there were no new drugs coming through,” he added. “The pipeline has opened up, but few are yet in clinical trials. It’s going to be a long time before they’re available to us.
“No matter how many new compounds we can produce to treat the individual, we need something at the community, the public health level.” That, he concluded, is why a new vaccine is so important.
Cite this as: BMJ 2012;345:e6981