The current tools are not enough to control tuberculosis
epidemic. The 2009 World Health Organization (WHO) Global Tuberculosis Control
Report says that the incidence of TB per capita continues to go down since 2004
however the decline is just one per cent per year which implies that TB will
not be eliminated for centuries if we conduct 'business as usual'.
The existing BCG vaccine which came into the market in 1921,
has limited effectiveness in preventing people from TB. Further, the BCG vaccine
which is used to prevent childhood TB may not be safe for children living with
HIV. That is why Aeras Global TB Vaccine Foundation and other agencies
including Bill & Melinda Gates Foundation are pushing hard to accelerate
research and development of safe and effective TB vaccines.
Currently there are seven vaccine candidate products in
different stages of the research pipeline around the world.
One phase-III clinical trial in Tanzania which was sponsored
by a US University, studied adults who were living with HIV, to see if there
was any reduction in disseminated TB in that population. The promising results
were announced in October 2008. "Aeras' vaccine advisory committee has
looked at this vaccine as a first step. Aeras is providing our manufacturing
expertise to see if it can be made at a larger scale" said Peg Willingham,
Senior Director, External Affairs, Aeras Global TB Vaccine Foundation.
"In our research pipeline at Aeras we have six vaccine
candidate products" shares Peg Willingham.
One vaccine candidate is being developed if it can replace
existing BCG vaccine with a better, modern and more effective BCG vaccine. This
candidate is expected to start phase-I clinical trial later this year.
"The BCG or the improved BCG alone would be strengthened by having a
booster shot - a different vaccine that will make the effect last longer and be
more effective" explains Peg Willingham.
So we have five boosters and one improved BCG vaccine
candidate products in the research pipeline, adds Peg.
By end of 2010, there will be two different TB vaccine
candidates being tested in 3 different phase IIb clinical trials. Phase IIb is
a mid-way safety and effectiveness trial between phases II and III.
"We are going to test them in different populations.
Our objective is to see if the vaccine will work in people of all ages, people
living with HIV, and those who have latent tuberculosis" says Peg
"In the TB vaccine field globally, currently there are
nine vaccine candidate products in different stages of clinical trials and many
others in earlier stages of development. They all look very safe currently and
we have seen some very early preliminary results that are promising but you
cannot say that a Phase I result in a few people will guarantee similar results
in large scale phase III clinical trial" explains Peg Willingham.
"With sufficient resources, a new TB vaccine could be
ready by 2020" says Peg Willingham.
These clinical trials will be conducted at the highest
international standards of ethics and quality because the product developers do
aim to get the product approval by the United States Food and Drug
Administration (US FDA) and such agencies in different countries around the
Contributed by: Bobby Ramakant