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Hope for Malaria Vaccine by 2015

British drug maker GlaxoSmithKline is seeking regulatory approval for the world’s first malaria vaccine after trial data showed that it had cut the number of cases in African children.

Experts say that they are optimistic about the possibility of the world’s first vaccine after the trial results.

Malaria, a mosquito-borne parasitic disease, kills hundreds of thousands of people worldwide every year.

Scientists say an effective vaccine is key to attempts to eradicate it.

The vaccine known as RTS,S was found to have almost halved the number of malaria cases in young children in the trial and to have reduced by about 25% the number of malaria cases in infants.

GlaxoSmithKline (GSK) is developing RTS,S with the non-profit Path Malaria Vaccine Initiative (MVI), supported by funding from the Bill & Melinda Gates Foundation.

“Many millions of malaria cases fill the wards of our hospitals,” said Halidou Tinto, a lead investigator on the RTS,S trial from Burkina Faso.

“Progress is being made with bed nets and other measures, but we need more tools to battle this terrible disease.”

The malaria trial was Africa’s largest-ever clinical trial involving almost 15,500 children in seven countries.

The findings were presented at a medical meeting in Durban, South Africa.

“Based on these data, GSK now intends to submit, in 2014, a regulatory application to the European Medicines Agency (EMA),” GSK said in a statement.

The company has been developing the vaccine for three decades.

The statement said that the hope now is that the Geneva-based World Health Organization (WHO) may recommend the use of the RTS,S vaccine from as early as 2015 if EMA drugs regulators back its licence application.

Testing showed that 18 months after vaccination, children aged five to 17 months had a 46% reduction in the risk of clinical malaria compared to unvaccinated contemporaries.

But in infants aged six to 12 weeks at the time of vaccination, there was only a 27% reduction in risk.

A spokeswoman for GSK told the AFP news agency that the company would file its application to the EMA under a process aimed at facilitating new drugs for poorer countries.

UK politician Lynne Featherstone, International Development Minister, said: “Malaria is not just one of the world’s biggest killers of children, it also burdens health systems, hinders children’s development and puts a brake on economic growth. An effective malaria vaccine would have an enormous impact on the developing world.

“We welcome the scientific progress made by this research and look forward to seeing the full results in due course.”

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Malaria Vaccine Shows Early Promise in Clinical Trials

By Rebecca Morelle, BBC Science

A malaria vaccine has shown promising results in early stage clinical trials, according to researchers.

Researchers found the vaccine, which is being developed in the US, protected 12 out of 15 patients from the disease, when given in high doses.

The method is unusual because it involves injecting live but weakened malaria-causing parasites directly into patients to trigger immunity.

The research is published in the journal Science.

Lead author Dr Robert Seder, from the Vaccine Research Center at the National Institutes of Health, in Maryland, said: “We were excited and thrilled by the result, but it is important that we repeat it, extend it and do it in larger numbers.” Continue reading “Malaria Vaccine Shows Early Promise in Clinical Trials”

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Malaria Deaths Fall over 20% Worldwide in Last Decade

There has been a fall of just over 20% in the number of deaths from malaria worldwide in the past decade, the World Health Organization says.

A new report said that one-third of the 108 countries where malaria was endemic were on course to eradicate the disease within 10 years.

Experts said if targets continued to be met, a further three million lives could be saved by 2015.

Malaria is one of the deadliest global diseases, particularly in Africa.

In 2009, 781,000 people died from malaria. The mosquito-borne disease is most prevalent in sub-Saharan Africa, where 85% of deaths occurred, most of them children under five.

An earlier report here incorrectly referred to a 40% drop in deaths.

It has been eradicated from three countries since 2007 – Morocco, Turkmenistan and Armenia.

The Roll Back Malaria Partnership aims to eliminate malaria in another eight to 10 countries by the end of 2015, including the entire WHO European Region.

Robert Newman, director of the WHO’s Global Malaria Programme, said “remarkable progress” had been made.

“Better diagnostic testing and surveillance has provided a clearer picture of where we are on the ground – and has shown that there are countries eliminating malaria in all endemic regions of the world,” he told an international Malaria Forum conference in Seattle.

“We know that we can save lives with today’s tools.”

Global eradication

A global malaria eradication campaign, launched by WHO in 1955, succeeded in eliminating the disease in 16 countries and territories.

But after less than two decades, the WHO decided to concentrate instead on the less ambitious goal of malaria control.

However, another eight nations were declared malaria-free up until 1987, when certification was abandoned for 20 years.

In recent years, interest in malaria eradication as a long-term goal has re-emerged.

The WHO estimates that malaria causes significant economic losses, and can decrease gross domestic product (GDP) by as much as 1.3% in countries with high levels of transmission.

In the worst-affected countries, the disease accounts for: Up to 40% of public health expenditures; 30% to 50% of inpatient hospital admissions; and up to 60% of outpatient health clinic visits.

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GlaxoSmithKline Malaria Vaccine Tests Show Hopeful Results

ATLANTA — The quest for the world’s first malaria vaccine appears to have taken a big step: A study in Africa shows experimental shots cut the risk of disease in young children by half.

The initial results from a final stage of vaccine testing were released Tuesday, and the vaccine’s developers called it a milestone in helping to tame one of the world’s most devastating killers.

However, the vaccine won’t be available for at least three years, as crucial further testing must be completed to see how well it works in infants and how long protection lasts. Then the vaccine must be reviewed by government agencies in Europe and in individual African countries.

“We still have a way to go,” Tsiri Agbenyega, lead researcher for the African study, said in a conference call with reporters.

The early results show the vaccine is only about 50 percent effective, significantly lower than the protection seen in more common vaccines. But some experts said it’s a vast improvement over the current situation, and could still save hundreds of thousands of lives.

Globally, malaria kills nearly a million people annually. More than 90 percent of them live in Africa, and most are young children and pregnant women.

Scientists have been trying for decades to develop a malaria vaccine and the one tested – developed by GlaxoSmithKline – is furthest along. Without a vaccine, efforts have concentrated on malaria drugs and other ways to prevent infection such as mosquito bed netting and insecticides.

The new vaccine targets a malaria parasite found in sub-Saharan Africa. Malaria spreads through mosquitoes, which bite people and flush malaria parasites into the bloodstream. The parasites cause bouts of high fever and can end in fatal organ failure.

In the United States, malaria has been eradicated since the early 1950s. Only about 1,500 cases are diagnosed in the U.S. each year, most of them travelers or immigrants from South Asia, sub-Saharan Africa or other places where malaria commonly spreads.

The new study – still under way – began in 2009 and involves more than 15,000 children in Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique and Tanzania.

The results focus on about 6,000 children ages 5 to 17 months. A year after three doses, the vaccinated children had about half as many cases of malaria as a group that didn’t get the vaccine.

Meanwhile, experts are waiting for results from research in a younger group – infants ages 6 to 12 weeks. That’s the age when children in sub-Saharan Africa are vaccinated against other diseases. Earlier vaccination also affords earlier protection.

Although there are an array of vaccines against viruses and bacteria, there has never been an effective vaccine against a parasite, which is a more complicated organism. Adding to the complexity is there are five species of malaria parasites – the new vaccine is designed specifically to protect against the deadliest one, which is common in sub-Saharan Africa.

GlaxoSmithKline paid for the study along with the PATH Malaria Vaccine Initiative, a program funded by the Bill & Melinda Gates Foundation. The results were released Tuesday at a malaria conference in Seattle and published by the New England Journal of Medicine.

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Malaria Vaccine Trial Raises Hope

By Matt McGrat,  Science reporter

Researchers are to expand a clinical trial of a new malaria vaccine after promising results in a preliminary study in Burkina Faso.

The trial was designed to test safety, but researchers found that vaccinated children had high levels of protection.

Described as a “most encouraging” result, a larger study involving 800 children is now to take place in Mali.

The scientists involved say they are hopeful that the vaccine will ultimately be very cheap to produce.

Around a hundred different malaria vaccine candidates have been developed to date but the MSP3 vaccine tested in Burkina Faso is only the second one to show a substantial level of protection against the illness.

The randomised, double blind study involved 45 children. It set out to test the safety of the vaccine but this follow up study found that children who received it had an incidence of the disease three to four times lower than children who did not.

Initially the children were split into three groups, with two of them receiving the experimental malaria vaccine developed by Dr Pierre Druilhe at the Pasteur Institute in Paris.

“Those two groups had very similar types of immune response, elicited by the vaccine, and the protection is almost identical, so it reinforces the confidence despite the fact that we are still dealing with a small group,” he said.

The vaccine is based on the fact that some adults in Africa acquire immunity because they are constantly exposed to the disease.

Early days

Dr Druilhe and his team discovered a key protein, MSP3, which provokes the body into producing antibodies that kill the parasite.

He said the protein is unique as it does not change much between different strains of the plasmodium parasite that causes malaria. This is believed to be a critical factor in developing an efficient vaccine.

He added: “We performed a large number of epidemiological studies that confirm that there was an association between that vaccine candidate and acquired protection, so when you immunise with this molecule you indeed induce protection.”

Another scientist involved with the Burkina Faso study was Dr Louis Miller, the former head of the Malaria Vaccine Branch of the US National Institutes of Health.

He said: “I was always in favour of this approach as it offered a chance in a field with few successes. I found the results of this preliminary study in Burkina Faso to be most encouraging.”

High transmission

Encouraged by the early results, Dr Druilhe said the trial has now been expanded to 800 children in Mali. But he remains cautious.

“There have been too many claims of effective vaccines so we have to remain very cautious. It has to be confirmed and we have started on work to do that confirmation. Essentially the trial in Mali is about 20 times larger, in extremely high transmission conditions, so it should yield very clear cut results – this will be black and white.”

The other vaccine candidate that has shown success against malaria is called RTS, S. It has been funded by the Bill and Melinda Gates Foundation and is set to go into production with pharmaceutical giant, GlaxoSmithKline.

But there are concerns that it could be expensive, especially for people in Africa and other regions affected by the disease.

Dr Druilhe says his vaccine could be a lot cheaper – perhaps half a dollar or less a bottle.

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The results of the Burkina Faso trial were published in The New England Journal of Medicine.

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Using Mosquitoes To ‘Vaccinate’ Against Malaria

Joanne Silberner,NPR

The parasite responsible for the intense fevers, chills, and headaches of malaria is very skilled at hiding in the in the body. That means vaccines don’t work all that well to prevent the disease.

So Dutch researchers are trying a new approach — “vaccinating” people by having them get bitten by mosquitoes carrying the malaria parasite, which is similar to how people get infected in the real world. And it seems that this technique may keep people safe from the disease more than two years later.

The Dutch way is different than the conventional vaccine approach of injecting people with bits and pieces of the malaria parasite, or a parasite that’s been weakened in the lab.

Those traditional approaches haven’t been working all that well in clinical trials. The Plasmodium parasite is notoriously tough to manipulate because it spends most of its time hiding inside red blood cells and liver cells, out of sight of the immune system. That’s one reason why it was able to kill 781,000 people in 2009. Most of those were children in developing countries.

In the Dutch experiment, 10 volunteers were bitten multiple times by malarious mosquitoes. The researchers then gave the volunteers an anti-malaria drug, chloroquine. (And yes, the researchers were very careful to pick a malaria type that can be vanquished by chloroquine, not a variety resistant to the drug.)

A couple of years ago, the researchers reported that this process works in the short run to protect against malaria. But that’s not such a big deal. People naturally infected by malaria build up an immunity that holds for several months.

What’s new is that the researchers went back to six of the volunteers 28 months later. Once again the volunteers allowed themselves to be bitten by malarious mosquitoes. Four of the six did not get infected. And the immune systems of the remaining two put up a fight – their infections were delayed (and quickly treated). The results were published online in The Lancet.

Wondering who would volunteer to be bitten by a malarious mosquito? Study author Robert Sauerwein of Radboud University in the Netherlands says most were university students. And the trial was designed pretty carefully.

A lot more work needs to be done to test this approach. This study was very small – only six people. And the researchers note that they may have stacked the deck a little – they used the exact same strain of malaria to infect, and to re-infect. And they worked with adults with mature immune systems, rather than children.

It’s not clear yet why the experimental vaccination protected longer than infection by mosquito in the field. The anti-malarial drug could have helped. Or maybe it was the intense exposure to multiple bites at the same time. Whatever the reason, they say, it’s worth investigating given how well the malaria parasite has been at outsmarting attempts to get rid of it.

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Vaccine-Delivering Nanoparticles May Help Fight HIV, Malaria

Engineers at MIT have come up with a new type of nanoparticle that could safely and effectively deliver vaccines for diseases such as HIV and malaria.

The new particles consist of concentric fatty spheres that can carry synthetic versions of proteins normally produced by viruses. These synthetic particles elicit a strong immune response – comparable to that produced by live virus vaccines – but should be much safer, says Darrell Irvine, author of the paper and an associate professor of materials science and engineering and biological engineering.

Such particles could help scientists develop vaccines against cancer as well as infectious diseases. In collaboration with scientists at the Walter Reed Army Institute of Research, Irvine and his students are now testing the nanoparticles’ ability to deliver an experimental malaria vaccine in mice.

Vaccines protect the body by exposing it to an infectious agent that primes the immune system to respond quickly when it encounters the pathogen again. In many cases, such as with the polio and smallpox vaccines, a dead or disabled form of the virus is used. Other vaccines, such as the diphtheria vaccine, consist of a synthetic version of a protein or other molecule normally made by the pathogen.

When designing a vaccine, scientists try to provoke at least one of the human body’s two major players in the immune response: T cells, which attack body cells that have been infected with a pathogen; or B cells, which secrete antibodies that target viruses or bacteria present in the blood and other body fluids.

For diseases in which the pathogen tends to stay inside cells, such as HIV, a strong response from a type of T cell known as “killer” T cell is required. The best way to provoke these cells into action is to use a killed or disabled virus, but that cannot be done with HIV because it’s difficult to render the virus harmless.

To get around the danger of using live viruses, scientists are working on synthetic vaccines for HIV and other viral infections such as hepatitis B. However, these vaccines, while safer, do not elicit a very strong T cell response.

Importantly, the particles also elicit a strong antibody response. Niren Murthy, associate professor at Georgia Institute of Technology, says the new particles represent “a fairly large advance,” though he says that more experiments are needed to show that they can elicit an immune response against human disease, in human subjects. “There’s definitely enough potential to be worth exploring it with more sophisticated and expensive experiments,” he says.

The work has been described in the Feb. 20 issue of Nature Materials. (ANI)

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Generic Malaria Drug Approval Granted to Glenmark Pharmaceuticals

The United States Food and Drug Administration (FDA) has granted Glenmark Pharmaceuticals final approval to sell a generic version of GlaxoSmithKline (GSK) malaria drug Malarone.

In April 2010, Glenmark settled a patent litigation with GlaxoSmithKline over atovaquone and proguanil hydrochloride 250 milligram/100mg tablets–the generic version of Malarone.

The Indian company can sell the generic tablets under a royalty-bearing license from GlaxoSmithKline in the third quarter of 2011, or earlier under certain circumstances.

KAM

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