Malaria Vaccine Research

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QUESTION

Is there any research to produce anti malaria vaccine, if not, why?

ANSWER

There are many teams of scientists working hard to try to produce a malaria vaccine. In fact, only last year, the preliminary results of a vaccine trial were published. The vaccine, called RTS,S, has been produced by GlaxoSmithKline and is in the midst of Phase III trials in Africa. The preliminary results showed approximately a 50% reduction in malaria incidence, though it is not clear how much of that protection came from the vaccine and how much should be attributed to the vaccine adjunct (a compound given with the vaccine to boost immune responses).

The preliminary results also did not include analysis of how much the vaccine prevented mortality due to malaria, and levels of protection against severe malaria appeared to be low. However, we will have to wait until 2014 for the full and final results of the clinical trial to be made available. In the meantime, other vaccine candidates are being developed, but there are many challenges to overcome.

For example, there are five different types of malaria that infect people: these differ significantly in the way they develop in the human host, and so a vaccine appropriate for one may not be effective against the others. Most vaccine researchers are focusing on Plasmodium falciparum, the most deadly form of malaria, and a vaccine effective against this parasite would certainly do the most to reduce malaria-related mortality. However, Plasmodium vivax also causes high morbidity, particularly in Asia and the Pacific, and so should not be overlooked.

Moreover, within each of these species exist different strains in different areas, each of which can be markedly different from a genetic perspective. Finally, we do not yet fully understand the complex ways in which our immune system reacts to malaria. As such, this presents a challenge to developing an effective malaria vaccine, though many scientists are willing to address this challenge and have made big inroads in the search for a safe, effective vaccine. For more information on current efforts to develop a malaria vaccine, please see PATH’s Malaria Vaccine Initiative.

Helping Those Affected with Malaria in Africa

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QUESTION:

What are some things that might be done to make the situation better for those most affected with malaria in Africa?

ANSWER:

Currently, the emphasis on decreasing the burden of malaria on those most affected in Africa is based on a combination of prevention, education, research and treatment. In more detail:

Prevention: This is arguably one of the keys to sustainably reducing malaria burdens and even eliminating infections. Central to this goal has been the distribution of long-lasting insecticide treated bednets, which prevent people from being bitten by infected mosquitoes while they sleep at night. Unfortunately, some recent research has just been published which suggests that bednets might be contributing to insecticide resistance in mosquitoes, as well as increased rates of malaria in adults due to decreasing natural immunity. As such, it may be that more research is needed in order to determine the most effective and efficient ways of using bednets to prevent malaria infection, particularly in high-risk groups like young children and pregnant women.

Education: Through education, people living in at-risk areas for malaria transmission can learn about ways to prevent the disease, as well as what to do if they suspect they are infected. Similarly, education is important for travellers visiting malarial areas, so they know the best ways in which to avoid being infected.

Research: Understanding the distribution, factors affecting transmission and the development of new strategies for control and treatment is going to be crucial in the fight against malaria, and particularly in high-burden areas such as Africa. Similarly, scientists are busily looking for new compounds to treat malaria, as well as the ever-elusive malaria vaccine. If such a vaccine could be developed, it would be a huge step forward in the fight against malaria.

Treatment: Hand in hand with treatment comes diagnosis; if a person can have their infection easily, accurately and cheaply diagnosed, then they will be able to access effective treatment more rapidly, thus improving their chances of a swift recovery. As such, countries in Africa are working hard to provide health systems capable of local diagnosis and availability of treatment, so that people don’t have to travel far to have their infections cured.

Taken together, these four strategies are having some success even in the world’s poorest and most malaria-endemic regions, especially in decreasing the number of malaria deaths. Decreasing the overall number of infections will be yet a greater challenge, but one which the world, especially through commitment to the Millenium Development Goals, is dedicated to overcoming.

Malaria Vaccine from Mosquito Saliva

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One of the more promising avenues of creating a vaccine for malaria involves going inside mosquitoes’ bodies — typically the source of the disease’s spread — to develop the key component of the vaccine.

Research published online in the journal Science today shows the barriers and future direction for that vaccine. A clinical trial of such a vaccine showed that it was safe, but that it didn’t confer immunity to enough of the study participants.

Read more, via My Health News Daily.

REVIEW: The Use of Intermittent Preventive Treatment in Pregnancy to Protect Against Malaria Infection

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Review of Le Port A, et al. (2011), ‘Prevention of Malaria during Pregnancy: Assessing the Effect of the Distribution of IPTp Through the National Policy in Benin’,  American Journal of Tropical Medicine and Hygiene, Vol 84 (Issue 2): pp 270-275

[Read more…]

Research Could Lead to Mosquitoes Being Susceptible to Diseases They Transmit

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Mosquitoes are becoming more resistant to current pesticides. That’s troubling to Kansas State University biologist Kristin Michel, as it means malaria and other mosquito-borne diseases will continue spreading. A recent grant from the National Institutes of Health may change all that.

Michel, an assistant professor of biology, is using the nearly $1.5 million grant for the four-year study, “The function(s) of serpin-2 in mosquito immunity and physiology.” Findings from this investigation into the role of the serpin-2 molecule in Anopheles gambiae — the African malaria mosquito — could stop the transmission of malaria and other mosquito-spread diseases by making mosquitoes susceptible to the very diseases they transmit.

As principal investigator, Michel and her laboratory team are focusing on definitively understanding the role of serpin-2 in the mosquito’s body. Serpins are a group of similarly structured proteins that can inhibit a group of enzymes that break down proteins called proteases. Serpin-2 controls certain proteases that create immunity against bacteria and fungi in the mosquito.

“Current insecticides used for controlling vector-borne diseases are chemicals that target an insect’s nervous system,” Michel said. “Because serpin-2 relates to a mosquito’s immunity, it could act as a novel insecticide target.”

Attacking this molecule could avoid or disrupt a response from the mosquito’s immune system that would otherwise protect the insect, she said.

The idea for the research came from a previous project conducted by Michel and fellow Kansas State researchers. By removing serpin-2 from the mosquitoes’ bodies, the researchers noticed melanization is affected. In insects melanin is used to encompass foreign objects that enter their body, like bacteria and parasites. This process prevents the insect’s immune system from constantly fighting the foreign body. It also causes pseudo-tumors in the mosquitoes once serpin-2 is removed.

“We don’t really quite understand yet why this happens, but we do know that the mosquito’s immune response is totally overamplified,” Michel said. “Instead of melanizing parasites or bacteria, the mosquito’s body attacks itself, getting melanotic pseudo-tumors throughout it.”

These pseudo-tumors appear as black dots on the insect’s thorax and abdomen. Afflicted mosquitoes that do not initially die from the tumors steadily lose interest in blood feeding over time.

“So what we’re going to do with this grant is to find out which proteases — since it’s most likely more than one — are being inhibited by serpin-2 for this whole process to occur,” Michel said. “Right now we have very little information about the cloud of proteases that float around in the insect, with regards to what they do and how they interact.”

Finding the proteases will require lots of detective work as more than 50 proteases are potentially being inhibited by serpin-2. However, Michel said, the most time-consuming portion may be collecting enough material from the mosquitoes to sample, as one mosquito yields about 0.1 microliters of bodily material.

Several co-investigators are also lending their expertise to the study. Michael Kanost, university distinguished professor and head of the department of biochemistry, is helping with expression of proteases and in vitro testing. Christopher Culbertson, associate professor of chemistry, is building microfluidics technology that will allow for better plasma analysis from the mosquitoes, potentially helping with the sample sizes. Scott Lovell, director of the protein structure laboratory at the University of Kansas, will use X-ray crystallography to visualize how serpin-2 binds to the proteases it inhibits.

“By the end of the study we really hope to say serpin-2 is a perfect target for an insecticide that prevents the mosquito’s immunity,” Michel said. “The next step will be then to find such chemicals. That’s where we’re hoping to take this research.”

via Newswise.

Key Malaria Scientists

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QUESTION:

I would like to know what key scientists are involved with the cure of Malaria.
Thanks

ANSWER:

There are literally hundreds of scientists around the world who are all working on different aspects of curing malaria. The complexity of the life cycle of the parasite means that there are lots of different areas of potential research, and some scientists specialise very precisely on one tiny aspect of the life cycle, hoping to find a way in which it can be exploited as a vulnerability, and used to develop new medications. I will resist naming any particular names, as that would be unfair to all the other scientists, whose work is equally important, that I don’t have space to list!

For example, some scientists devote their attention to the reproduction of the parasite inside human red blood cells or the process of infection; a paper came out very recently which looked at ways in which the malaria parasite uses host proteins to fulfill its own reproductive processes, and how that cycle can be disrupted as a way of treating malaria. A review of that paper will be appearing on this website in the very near future. Other scientists focus on the life cycle of the parasite inside the mosquito, or indeed even just the mosquito itself; some very cool research came out last year, for example, by scientists at Cornell University on how manipulating proteins in the mosquitoes’ kidneys can prevent them from successfully flying off after drinking human blood, thus killing them. Other scientists focus on treatment; for example, the quest for a vaccine against malaria has been a lifelong devotion for many teams of scientists around the world. Other cutting edge research involves looking at whether existing drugs can be used to tackle malaria; recently, it was discovered that a common drug used for treating cancer also has anti-malarial effects.

Finally, there are a whole army of scientists who work away from the lab at ways of curing malaria; this includes, for example, epidemiologists who look at disease distribution and burden at different scales, and geospatial statisticians who apply their research to informing health professionals where the highest risk locations for malaria are, and so treatment and resources can be targeted effectively and efficiently. Many of these control interventions also involved scientists, whose job is to evaluate the success of such operations, and design strategies that can even more rapidly deliver malaria diagnosis, treatment and prevention information to the people who need it most.

Hopefully by now you will see why it is impossible to give you a list of the most important malaria scientists in the world; there are so many people working on so many different facets of treating the disease that I would never be able to include them all! However, we are encouraging many of the scientists who work on malaria to join this website; as such, keep an eye on the membership and feel free to contact any members who are engaged directly in research; I am sure they would be happy to give you more information as to the research groups working on specific areas of malaria control.