10/14/10

GLOBAL:  Hope for Expanded Protection Against TB

The Aeras Global TB Vaccine Foundation is testing several TB vaccine candidates, including one that would improve upon the Bacille Calmette-Guérin (BCG) vaccine given to infants by providing long-term protection against all forms of TB instead of just providing protection against pediatric TB. The AERAS-422 vaccine is about to undergo trials in the United States, the foundation said.

Aeras also is collaborating with the Dutch biopharmaceutical firm Crucell on four vaccine candidates designed to be boosters for teens and children who received BCG as infants. Phase IIb clinical trials for these will begin soon in Africa and India.

"We hope that at least one of the new vaccine candidates will prove to be more efficacious in preventing TB, not just in infants, but in all age groups and in varied populations, such as people infected with HIV," said Anthony Hawkridge, a senior researcher at Aeras. "We have data from animal studies and from early phase clinical trials, but it is not possible to extrapolate from that and say that the new vaccines will definitely work."

"However, we are very optimistic about the fact that there are so many apparently good candidates coming through," Hawkridge said. "And we are very hopeful that at least one of them will 'go all the way.'"

Experts have been hoping to have a new TB vaccine by 2015-16, Hawkridge said. "I believe that the experts are now saying that it may take a bit longer, possibly until 2020," he said. "Given that the first Phase IIb trial [which will take place in Kenya] is not yet fully enrolled, requires two years of follow-ups, and there still needs to be a Phase III, which will take at least three years to conduct, I cannot see a product being registered before 2017. Maybe 2020 is more realistic."

"Without a better TB vaccine, it will be difficult to turn the TB epidemic in Africa around," said Hawkridge.

Source: Inter Press Service (10.08.10):: Aimable Twahirwa; Courtesy of the CDC National Center for HIV, STD, and TB Prevention