Cape Town - A novel tuberculosis vaccine, currently being tested in South Africa as a booster to the childhood BCG vaccine, could turn around the spread of TB if it is proven to be effective.
The M72/ ASO 1E vaccine candidate is set to be tested on more than 3 500 healthy adults in South Africa, Kenya and Zambia over the next four years.
Jointly led by NGO Aeras and GlaxoSmithKline, the Phase 2b clinical trial is to be tested on at least 2 500 South Africans.
Dereck Tait, clinical director of Aeras, said the new vaccine was being tested on adults as the current BCG vaccine was less effective as one grew older. A BCG is given to all newborns as part of the Department of Health’s immunisation programme.
According to the World Health Organisation, South Africa has the world’s third-largest TB burden after India and China, with about one percent of the population developing active TB each year. Mortality statistics in South Africa show that TB is the leading overall cause of natural death.
Tait said if the trial was successful, an adult TB vaccine would have a much bigger impact in controlling the TB epidemic than a childhood vaccine.
The first few participants in South Africa had been tested after animal studies showed that the vaccine was suitable to move into clinical trials. “The data from these studies did not raise any safety issues and also demonstrated that immune responses which had an effect on TB infection were generated,” he said.
Meanwhile a large-scale UCT clinical trial, which tested the use of cortisteroids for the treatment of TB pericarditis – that causes fluid build-up and compression of the heart – has shown they made no difference in the mortality rate. Even more significantly, in HIV-positive patients, steroid treatment increased the risk of cancer.
However, steroids were found to offer anti-inflammatory benefits by reducing fibrosis (constriction) of the heart and preventing scarring.
Professor Bongani Mayosi, lead investigator and head of medicine at Groote Schuur Hospital and UCT, said the new findings would change clinical practice.
Cape Argus