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[afro-nets] The World's First TB Vaccine in Eighty Years


  • Subject: [afro-nets] The World's First TB Vaccine in Eighty Years
  • From: Leela McCullough <leela@healthnet.org>
  • Date: Thu, 28 Oct 2004 11:29:15 -0400
  • Cc:

The World's First TB Vaccine in Eighty Years
--------------------------------------------
(Copied as fair use)

The Nation (Nairobi)
NEWS
October 28, 2004
Posted to the web October 28, 2004

By Gatonye Gathura
Nairobi

The first tuberculosis (TB) vaccine to be developed in more than
80 years has passed safety trials and shown encouraging signs
that it will work. The vaccine which is much stronger than the
current one - BCG - has been developed by British scientists and
has the capacity to halt the growth of the disease.

A study in Nature Medicine and extensively reported by The Times
and BBC early this week suggests that the new vaccine could be
of particular importance, particularly because of the current
increasing incidence of TB cases.

Although the reports indicates that the vaccine will be of par-
ticular importance to developing countries, TB has been on the
rise across the globe for lack of newer powerful vaccines and
the emergence of HIV which lowers the body's immunity.

In England, the number of cases of TB has risen by 25 per cent
over the last decade. The disease claims about 350 lives a year
in the UK.

TB is believed to be present in about one-third of the world's
population, around two billion people, although many people do
not develop the disease.

The only existing vaccine, BCG is thought to offer protection
for around 15 years. But it is not effective for everyone. In
some parts, only around two thirds of those who receive the vac-
cination are believed to be protected. Some trials have sug-
gested protection could be as low as 30 per cent.

The new MVA85A vaccine was tested in Oxford, where school chil-
dren no longer routinely receive BCG.

The three-year study, which was funded by the Wellcome Trust Re-
search Charity, involved 42 adults aged 18 to 55, who were di-
vided into three groups.

Two groups had never been vaccinated with BCG. One of these was
given BCG and the other MVA85A.

People in the third group, who had previously received BCG, were
given MVA85A as a boost.

In those who were only given MVA85A, the trials showed it was
safe and produced a high number of T 'helper' cells, which fight
disease.

Those who had previously had BCG and were given MVA85A revealed
a far greater number of T cells, in some cases up to 30 times
the levels produced in the other groups.

The researchers now plan to test the research in the developing
world. A trial is already underway in The Gambia - where TB is
endemic and babies are given BCG within 24 hours of birth. In
the UK, BCG is usually administered at the age of 13.

The trial showed that the combination multiplied the immune sys-
tem's response to TB up to 30-fold when compared with BCG alone
- the largest response ever recorded in a vaccination trial.

However, the researchers are still aware that a usable vaccine
is still years away but say it is a "practical and efficient
strategy for enhancing the prolonging immunity in TB-endemic ar-
eas".

According to the World Health Organisation, someone is infected
every second with the bacterium responsible for TB, Mycobacte-
rium tuberculosis. It is present in about a third of the world's
population, about two billion people, although the vast majority
do not develop the disease.

But even more exiting are reports that British scientists have
made a breakthrough which allows vaccines to be stored for years
without refrigeration.

This is an exciting development, especially for poor countries
as it could cut costs of transporting and storing vaccines by a
huge margin.

Literally in the whole of Africa and other poor countries, vital
vaccines frequently fail to work or have to be thrown away be-
cause they have been spoiled by not being kept cold enough.

The technology uses a natural process seen in living organisms
like the desert-dwelling resurrection plant, which dries up com-
pletely in drought conditions, only to burst into life when rain
arrives, tens or even hundreds of years later.

Dr Bruce Roser of Cambridge Biostability, last week said that
trials on animals had gone very well, and clinical trials of the
procedure on humans could be started within three years.

He explained how the resurrection plant survives over long peri-
ods in the absence of liquid thanks to a sugar which becomes as
hard as glass when dry.

"They use an unusual but simple sugar which has the property of
turning into a thick syrup when it dries out, rather than crys-
tallising," he told the BBC Radio 4 Today programme.

"We have taken this technology and made it work on the lab
bench. We have put these vaccines in a solution of this syrup.

"We dry it and it turns into a syrup which becomes more and more
viscous as we remove more and more water until imperceptibly it
solidifies as a glass.

"It is very similar to fossilised insects trapped in amber which
are preserved for millions of years."

The technique has already been tested on four commercial vac-
cines, which were found to be "stable and efficacious" in animal
trials.

The Cambridge-based company has received a grant of £950,000
from the Department for International Development (DFID) to de-
velop a five-in-one vaccine for children in developing coun-
tries.

It is hoped that the new technique may allow 10 million more
children worldwide to be vaccinated within existing budgets.

The five-in-one vaccine - against measles, rubella, tetanus,
whooping cough and diphtheria - will be manufactured by Panacea
Biotec, based in Delhi, a leading Indian biotechnology company.

Copyright © 2004 The Nation. All rights reserved. Distributed by
AllAfrica Global Media (allAfrica.com).


--
Leela McCullough, Ed.D.
Director of Information Services

SATELLIFE
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