[e-drug] The World's First TB Vaccine in Eighty Years

["Leela McCullough" <leela@healthnet.org>]

E-DRUG: The World's First TB Vaccine in Eighty Years
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[Copied as fair use; WB]

The World's First TB Vaccine in Eighty Years 

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 particular 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 vaccination are believed to be protected. Some trials have suggested protection could be as low as 30 per cent. 

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

The three-year study, which was funded by the Wellcome Trust Research Charity, involved 42 adults aged 18 to 55, who were divided 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 system'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 areas". 

According to the World Health Organisation, someone is infected every second with the bacterium responsible for TB, Mycobacterium 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 eciting 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 because 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 completely 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 periods 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 crystallising," 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 vaccines, 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 develop a five-in-one vaccine for children in developing countries. 

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


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