A booster shot appears to improve tuberculosis (TB) resistance in previously vaccinated adults, according to new research in South Africa.
The study has been published online ahead of print publication in the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.
"The world urgently needs new, better vaccines against TB," said Willem Hanekom, M.B.Ch.B., associate professor and co-director, South African Tuberculosis Vaccine Initiative (SATVI). "It is important to test the safety of these vaccines in settings where TB is very common, such as South Africa."
Every year 1.7 million people die from TB, according to the World Health Organization. This study is the first to report results from testing an adenovirus-35-based vaccine in humans. Adenovirus-35 is attractive to vaccine developers because fewer humans have been exposed to this strain of the virus, compared with many other adenoviruses, and the immunity from exposure is therefore less likely to interfere with the vaccine's action.
The Aeras-402 vaccine, developed by Aeras Global Tuberculosis Foundation and Crucell, was made by weakening the virus in the lab, so that it can no longer replicate and cause disease. Parts of the TB bacterium that are important to stimulate the immune system (antigens) were then inserted into the virus.