Setback for first malaria vaccine in African trial

LONDON Fri Nov 9, 2012 9:11am EST

A young girl with malaria rests in the inpatient ward of the Malualkon Primary Health Care Center in Malualkon, in the South Sudanese state of Northern Bahr el Ghazal, June 1, 2012. REUTERS/Adriane Ohanesian

A young girl with malaria rests in the inpatient ward of the Malualkon Primary Health Care Center in Malualkon, in the South Sudanese state of Northern Bahr el Ghazal, June 1, 2012.

Credit: Reuters/Adriane Ohanesian

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LONDON (Reuters) - The world's first potential malaria vaccine proved only 30 percent effective in African babies in a crucial trial, calling into question whether it can be a useful weapon in the fight against the deadly disease.

The surprisingly poor result for the vaccine, which GlaxoSmithKline has been developing for three decades, leaves several years of work ahead before a protective malaria shot could be ready for countries that desperately need one.

Malaria, a mosquito-borne parasitic disease, kills hundreds of thousands a year, mainly babies in Africa, and scientists say an effective vaccine is key to hopes to eradicate it.

Philanthropist Bill Gates, who helped fund the GSK vaccine's development, said further research was now needed to see whether and how it might be used.

"The efficacy came back lower than we had hoped, but developing a vaccine against a parasite is a very hard thing to do," he said in a statement.

Results from the final-stage trial with 6,537 babies aged six to 12 weeks showed the vaccine provided "modest protection", reducing episodes of the disease by 30 percent compared to immunization with a control vaccine, researchers said on Friday.

That efficacy rate a year after vaccination is less than half the 65 percent in an earlier trial in babies which analyzed protection rates after six months. It is also a lot less than the 50 percent rate seen in five to 17 month-olds.

Vaccinating babies, rather than toddlers, is the preferred option, since the new vaccine could then be added to other routine infant immunizations. A separate program for older children would involve a lot of extra costs.

Eleanor Riley, a professor of immunology at the London School of Hygiene and Tropical Medicine said the results showed that GSK's vaccine, called RTS,S or Mosquirix, is potentially useful, but "not the complete solution".

"The slightly lower than expected efficacy will ... affect the cost-benefit analysis that health providers and funders will have to undertake before deciding whether the vaccine represents the best use of limited financial resources," she said.

NOT GIVING UP

Despite the setback, Britain's top drugmaker said it would push ahead with developing RTS,S and GSK Chief Executive Andrew Witty said it could be an important tool in fighting malaria.

"We've been at this for 30 years, and we're certainly not going to give up now," he told reporters on a conference call.

GSK does not expect to make any profit from the vaccine, which would only be sold in poor countries.

Witty reiterated a promise that if RTS,S is ultimately approved for market, it would be priced at cost of manufacture plus a 5 percent margin, and the margin would be reinvested by GSK in malaria research.

Given the target market, it is governments and international groups that will fund the vaccine's roll-out, and they now need more positive data before deciding whether it is worth buying.

"We will have to have more information to give us a clearer idea as to how useful this vaccine will be," said Seth Berkley, CEO of the GAVI Alliance, which funds bulk-buy vaccination programs for poorer nations.

In particular, Berkley told Reuters he wanted to see longer-term data, including the effect of booster shots, and an analysis of how the vaccine performed in different settings.

Details of the malaria trial, which is Africa's largest ever clinical trial involving almost 15,500 children in seven countries, were presented at a medical meeting in Cape Town and published online by the New England Journal of Medicine.

Witty said he would have liked to have seen efficacy rates of around 50 percent in infants, but stressed that more data would become available before the trial ends in 2014 which may throw more light on why rates of success are so variable.

"It may open up a more customized approach to how this potential vaccine gets used," he said.

Malaria is caused by a parasite carried in the saliva of mosquitoes. It is endemic in more than 100 countries worldwide and infected around 216 million people in 2010, killing around 655,000 of them, according to the World Health Organisation.

Control measures such as insecticide-treated bed nets, indoor spraying and anti-malaria drugs have helped cut cases and deaths significantly in recent years, but scientists say it will take an effective vaccine and many more years work to wipe out malaria.

Scientists around the world are working on other potential malaria vaccines but RTS,S is by far the furthest ahead in development.

(Editing by Mark Potter and Jon Hemming)

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Comments (5)
Herbert1212 wrote:
How about attacking the source..Mosquitos
Spraying the walls and eaves of houses once or twice a year with DDT, a powerful spatial repellant keeps 80-90% of mosquitoes from even entering a home; irritates any that do enter, so they don’t bite; and kills any that land. DDT is a long-lasting mosquito net over entire households. No other chemical, at any price, can do this. And no one (certainly not any eco pressure group) is working to develop one.
This miracle chemical had helped prevent typhus and malaria during and after World War II, and completely eradicate malaria in the United States, Canada and Europe. It was then enlisted in an effort to rid the entire world of malaria. After initial successes, DDT ran into an unexpected roadblock in 1969.
The war on DDT was never about protecting people or birds. It was, and is, about power, control, money and ideology – regardless of the resultant human misery, disease and death.

For the new Environmental Protection Agency, it was about power and politics. As the greens’ campaign to ban DDT intensified, EPA Administrator William Ruckelshaus convened a scientific panel, which held six months of hearings, compiled 9,312 pages of studies and testimony, and concluded that DDT was safe and effective and should not be banned.
Nevertheless, without attending a single hour of hearings or reading a page of the report, Ruckelshaus banned US production and use of DDT in 1972 – at a time when over 80% of the chemical was being exported for disease control. He later said his decision had nothing to do with cancer. He had a political problem, he said, and he fixed it. How nice for malaria victims.
Three billion humans dead so far from malaria … and counting. And green ideologues work tirelessly to ensure that the callous, needless global death toll continues to rise.

Nov 09, 2012 7:11pm EST  --  Report as abuse
TruthinChrist wrote:
Well the truth is that NO vaccine prevents disease. Vaccines have NEVER been proven to prevent disease. It’s only a THEORY that if you bombard the immature immune system at birth that the immune system will be stronger in preventing disease. In truth, vaccines wreak havoc on the immune system and cause more disease (Lou Gehrigs, cancers, arthritis, multiple sclerosis, autism, crib death, ETC!) The ONLY way to strengthen your immune system is with non-GMO, unprocessed food, natural exercise and stress management. If you have a strong immune system you can fight off any exposure to bacteria or a virus. That’s why God gave us an immune system in the first place. I would not recommend using DDT as Herbert below recommends in his comment. I would use other natural mechanisms that are on the market. Vaccines are the biggest money-making scam in our history or man-kind.

Nov 10, 2012 8:27am EST  --  Report as abuse
Herbert1212 wrote:
DDT works far better than many pesticides now in use, many of which are just as toxic to birds, mammals, fish and other aquatic organisms. And with DDT unavailable, many mosquito-control authorities are depleting their budgets by repeated spraying with expensive, short-acting and marginally effective insecticides.

http://www.aaenvironment.com/DDT.htm

Nov 10, 2012 2:47pm EST  --  Report as abuse
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