PNAS Modeling Study Finds TB Vaccines for Adolescents/Adults Cost-Effective Even With Low Efficacy
ROCKVILLE, MD, USA, OCTOBER 8, 2014 — A new study published in the Proceedings of the National Academy of Sciences released this week finds that a tuberculosis (TB) vaccine could have an important impact in reducing TB-associated disease and death even if the vaccine had relatively low efficacy, provided that the vaccine was targeted for use in adolescents and adults rather than infants. Each year, approximately 9 million people develop TB and 1.3 million die of the disease. Approximately 2 billion people worldwide are infected with Mycobacterium tuberculosis (Mtb), the bacteria that causes TB, in spite of the widespread use of the infant TB vaccine, BCG.
Using a model with data from 91 countries, the report demonstrates that novel vaccines targeted at adolescents/adults could prevent TB and be cost-effective, or even cost-saving, before 2050 if the efficacy were as low as 20% with a 10 year duration. "Trials among adults should be powered to detect low efficacies," say the authors. In low-income countries, where the burden of TB is greatest, an adolescent/adult vaccine with a ten-year duration and 60 percent efficacy could prevent 17 million cases of TB between 2024 and 2050. If targeted at infants, the model suggests that fewer than one million cases of TB would be averted.
The study was authored by researchers at the London School of Hygiene and Tropical Medicine and the World Health Organization and funded by Aeras, a non-profit biotechnology organization that advances development of tuberculosis vaccines for the world.
"Our results suggest that to achieve the 2050 elimination goals, future TB vaccine development should focus on vaccines targeted at adolescents/adults, even if only relatively low efficacies and short durations of protection are technically feasible," write the authors.
"Adolescents and adults are the main sources of the spread of TB," said Tom Evans, CEO of Aeras. "To have a rapid and meaningful impact on TB, and eliminate this deadly disease by 2050, these results strongly suggest that we should focus investments in developing TB vaccines, and concentrate of adolescent and adult populations.
Some $600 million of investments over the past decade have produced a robust portfolio of TB vaccine candidates, with more than a dozen candidates currently in clinical trials