Immunizing Mosquitoes To Fight Malaria
By Jesse Emspak, International Business Times
Millions of people in the tropics suffer from malaria, a mosquito-borne disease that has been difficult to treat and which costs many developing countries millions of dollars per year in lost productivity. Up to now, efforts at controlling it have focused on attacking the parasites that cause it, keeping mosquitoes from biting, or killing the insects.
But at Johns Hopkins University, Rhoel Dinglasan, an entomologist and biologist, decided to try another tack: immunizing mosquitoes.
Mosquitoes carry a species of parasite called plasmodium. The parasite lives in the mosquito’s gut. The parasites then spread to the mosquito’s salivary glands, and when the insect bites an uninfected person, they enter the bloodstream. At that point the plasmodium goes from the blood to a person’s liver, where it matures, escaping to the bloodstream to infect the red blood cells in a form called a merozoite.
Once in the blood cells, the parasite reproduces until the red cell bursts, releasing more merozoites. This cycle repeating itself causes the characteristic fever, chills and ache associated with the disease.
…
When a mosquito bites an infected human, it takes up some of the gametocytes.They aren’t dangerous to people at that stage. Since plasmodium is vulnerable there, and that is the point that Dinglasan chose to attack.
Full story here
================================
Here’s the very first Press Release from Johns Hopkins university citing this idea:
Vaccine Blocks Malaria Transmission in Lab Experiments
Researchers at the Johns Hopkins Malaria Research Institute have for the first time produced a malarial protein (Pfs48/45) in the proper conformation and quantity to generate a significant immune response in mice and non-human primates for use in a potential transmission-blocking vaccine. Antibodies induced by Pfs48/45 protein vaccine effectively blocked the sexual development of the malaria-causing parasite, Plasmodium, as it grows within the mosquito. Sexual development is a critical step in the parasite’s life cycle and necessary for continued transmission of malaria from mosquitoes to humans. The study is published in the July 22 edition of the journal PLoS ONE.
“Development of a successful transmission-blocking vaccine is an essential step in efforts to control the global spread of malaria. In our study, we demonstrate the relative ease of expression and induction of potent transmission-blocking antibodies in mice and non-human primates. This approach provides a compelling rationale and basis for testing a transmission-blocking vaccine in humans,” said Nirbhay Kumar, PhD, senior author of the study and professor in Johns Hopkins Bloomberg School of Public Health’s W. Harry Feinstone Department of Molecular Microbiology and Immunology.
For the study, the research team expressed full-length Pfs48/45 in E. coli bacteria to produce the vaccine. Previous attempts to fully express the protein had not been successful. The vaccine was first given to mice in the laboratory. The vaccine was also tested in non-human primates (Olive baboons) in Kenya with similar results. According to the study, a single-dose vaccine provided a 93 percent transmission-blocking immune response, reaching greater than 98 percent after a booster given several months later.
“This is an exciting beginning to what might become an important tool in the arsenal for malaria control and progressive elimination of malaria transmission,” said Kumar. There is no animal reservoir for human malaria and in that regard it is possible to gradually reduce malaria transmission to a point of almost eradication. However, Kumar cautioned that more research is needed to achieve that goal. For one, similar research efforts are needed to reduce transmission of Plasmodium vivax, another major human malaria parasite.
Malaria affects greater than 500 million people worldwide and is estimated to kill over one million people each year, most of whom are children living in Africa.
In addition to Kumar, “A Potent Malaria Transmission-Blocking Vaccine Based on Condon Harmonized Full Length Pfs48/45 Expressed in E. Coli” was published by Debabani Roy Chowdhury, a postdoctoral fellow of the Johns Hopkins Bloomberg School of Public Health; Evelina Angov of the U.S. Military Malaria Vaccine Program; and Thomas Kariuki of the Institute of Primate Research in Nairobi, Kenya.
The research was supported by grants from the National Institutes of Health and the Johns Hopkins Malaria Research Institute.
There already exists a very effective chemical for immunising mosses, DDT!
Jesus (or Allah if you are so inclined), how lefty does the JH idea sound? Immunise mosses so we don’t have to kill them!
Mailman
Mailman,
Despite their deleterious effects on humans, mosquitos are not entirely useless to the ecosystem, providing important food for small animals. While their ability to spread diseases rank them as a harmful parasite, eradicating their ability to spread a disease like malaria is going to be more advantageous in the long term than eradication of the entire species. I’ve never really liked the bleeders, but DDT is not an immunization, it’s buggy genocide.
Very clever!
DDT, and other incesticidal approaches, not only rid the people of pesky mosquitos but also a range of other disease carrying and crop destroying pests.
Yet another triumph of intellect over intelligence! It may have limited local application but it certainly isn’t the global solution millions of people need to insect borne diseases.
Cool research, 40 years late — Meanwhile, let’s put DDT back in production and save a million African kids under the age of five from dying of the scourage of malaria each year. Somewhere around 35-50 milion African children have died since the EPA’s DDT hoax was unleashed on the world.
See the pattern?
Weird, I was flicking through the channels last night and stopped at a BBC documentary that said that outright eradication in some areas may need to be considered because malaria cases were up to 50% higher than had been reported to date.
They went as far as they could without expressly saying that DDT should be reintroduced, which left me with a wry smile given that they’ve been major opponents to it to date. I wonder if it ever crosses their minds as to how many lives have been lost as a result of that opposition.
I’ll never forget a time walking through Epping Forest in London and getting dive bombed by the little buggers, and even though I was wearing a jumper I had thirty bites all along my shoulders. Other times, when living in Dagenham (very close to marshland), my arms would regularly swell up (once to nearly twice its size) as a result of them.
Maybe they do make good fodder for birds, hell, maybe that might have been a reason why the birds went somewhere else, but I for one wouldn’t miss them.
The argument for immunization is that it is more effective, cheaper, and with less side effects, than trying to kill all mosquitoes. Which is not going to happen, anyway. Objecting to it and preferring DDT is just silly. It is precisely the same error that the AGW lobby makes when favoring wind turbines: preferring an ineffective solution over an effective one, because it accords with your irrational prejudices.
OK, but who rounds up the mosquitos and makes them all stand in line so they can get their shots with those tiny, tiny little needles? And will the mosquitos have to pay for the shots out of pocket or will their Union cover the cost?
NovaReason,
Certainly mosquitos, especially in the larval stage, are a food source for many species. As adults they even provide pollination for some plants. However, there is no known obligate feeder related to mosquitos and there is no known plant for which the mosquito is sole pollinator. So while “entirely useless” would certainly be an over-reach, to suggest the world would be better off without them is not an over-reach, either.
Since the travel distance of mosquitoes is rather small the DDT or similar pesticide solution has generally been the most cost effective. Once an area is cleared of malaria the spraying stops, as in large parts of the developed nations. One is not advocating elimination of all mosquitoes.
An interesting idea but I believe there are serious drawbacks. On the plus side the image of microscopic nanorobots or nanites sticking needles in mosquitoe limbs does have a certain ironic appeal to it.
The possibility of immunizing the mosquitoes to plasmodium is an intriguing possibility. The next important step will be to model the process to see if immunization will work at the population level.
I support all attampts at bugocide where mozzies are concerned. The food niche would soon be filled with something less harmful. Biting blackflies and no-see-um’s can go the same route.
In summer a moose loses about a litre of blood per week to mosquito bites.
To their credit, mozzies are significant pollinators in the Arctic. The problem there is not the presence of mozzies but the absence of frogs to eat them. If it warms slightly balance will be restored. A single leopard frog hopped off a truck from Arctic Red in Inuvik and survived for 3 years, croaking his lonely way throughout each summer. So they can survive.
We should air-drop tadpoles across the whole NWT!
Spraying of homes with DDT doesn’t eradict mosquitoes, it just keeps them away from human habitations. The ones which still come, die. The stability of DDT is a boon in this application because you need to spray only once a year. Spraying tons of this stable compound on crops is another matter and is not the subject of debate. Withholding DDT against malaria is passive genocide and has killed as many as the nazis, commies and jap militarists together. The day a better solution than DDT is available, it will be used.
Smart idea. I like it. Surprised no one thought of it before!
First of all DDT is a safe and effective insecticide when used as directed, it is almost completely non-toxic to mamals, people used to eat it to demonstrate it’s low toxicity, and it was used for delousing people quite extensively. To supress mosquitoes the DDT is sprayed on the house and it’s patios, particularly on the inside, and the home’s mosquitoe nets are sprayed. DDT then kills any mosquites that alite on a treated surface, and because of it’s low durattion, an application lasts for years. DDT is banned for outdoor uses like crop spraying and is currently expensive due to very limited production. My magic eightball says that will change when people realize that it is the only thing that will get rid of their bedbugs without having to get a second mortgage.
Jimmy Haigh says:
October 30, 2010 at 5:18 am
Smart idea. I like it. Surprised no one thought of it before!
___________
The idea has been around for a long time actually. It was originally developed at the NIH, and I worked on the technology of vaccine production with them, with a protein called Pfs25. Here’s one of about 10 papers that were published on the subject back then:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC303304/
It was quite an success academically but never seemed to gain any traction at the field development level, as other vaccine strategies (which turned out to be losers) were ahead of transmission-blocking strategies in the queue for the relatively meagre development funding at the time.
Maybe these guys will have more success with that. Good luck to them.
Funny how scientists will go to such great lengths to find a solution other than DDT for malaria, but refuse to let go of embryonic stem cell research when adult stem cell research is available and also more successful. Almost makes you wonder at the kind of morality that exists in the field.
The article says malaria “costs many developing countries millions of dollars per year in lost productivity”, so I thought adding the millions of children’s deaths per year would be worthwhile, but ‘tarpon’ (comment above) already did.
Pesticides need to be seen in context. The hard fact is, it’s a trade-off. DDT might be harmless, and I’m happy to avoid it, just in case. If I were a Tanzanian sharecropper, I would have a different view. I remember when I was a kid in Britain, and Paraquat was banned. Many years later, I saw it on sale in Guatemala, and was shocked, then realised that it’s better to spray your house with Paraquat, otherwise you won’t live long enough to get cancer anyway.
If African families didn’t have to walk down to the river or lake or swamp to get water, ie. if they had plumbing, they would be much less prone to malaria. Immunizing mosquitoes is more fun though, and employs more Western scientists. Even more fun and expensive is the Gates Foundation’s proposal to eliminate malaria via genetic engineering. For us geeks, how to raise tropical living standards is boring compared with tinkering with DNA.
The problem with finding an answer to malaria is that we already have one. DDT works very effectively having cut deaths to 50,000 annually before anti-DDT hysteria forced it back up to 2 million. Like many such problems (cheap CO2 free nuclear power, ending hunger by GM foods) the answer already exists. The deeper problem is that the Luddites don’t want to ban new technology because they think it is harmful – they pretend to think it is harmful because they want to ban new technology. You will see that as soon as fusionn becomes practical the enthusiasm for it among “environmentalists” will evaporate. Searching for new technological solutions to probelms which already have such solutions is playing into their hands.
The only answer is to take them on head on – in this case oppose DDT hysteria.
There seems to be no point in taking a vaccine for malaria when an effective, cheap and safe remedy is already available. Miracle Mineral Solution (MMS) was developed by a guy called Jim Humble for when he was working in mosquito infested areas in Sth America. He’s in his 70s now but claims to have already successfully treated tens of thousands of patients in places like Africa for malaria. He says MMS can eradicate the body of malaria within a day. The reason this has not made headlines, I believe, is because there is no real money to be made from it.
http://jimhumble.biz/biz-generalinfo.htm
If you are up to it you can make it yourself (the ‘recipe’ is on the net) or you can buy it in a ready-to-use form off the net. The main ingredient is supposed to turn into regular salt an hour or two after taking it so it’s apparently innocuous to healthy cells in the body but not to parasites etc. The theory of how it works is that anaerobic cells are destroyed fairly quickly whereas normal aerobic cells stay healthy, or something similar to this.
I tried it myself (though not for malaria) and within 3 days it cleared up a severe heat-related allergy I’d had for years. That’s the reason I suggest the above info might be a better alternative than a vaccine.
http://mms-articles.com/
Personally, I think Congress should just pass a law making malaria illegal. That should solve the problem once and for all.
The really clever thing would be to stop the little blighters biting me in the first place. That would be worth a nobel prize.
I wrote a paper as an undergrad-supporting DDT for the reasons above. There are still
people in the area that won’t talk to me. To me the non use of DDT is another form of Genocide. There are Greenies that go to bed with the gnawing fear of healthy, happy prosperous, dark skinned people…
appologies to H.L. Menken
Rod, you may be a little mixed up about the paraquat. Actually, it is a herbicide, not an insecticide. I was involved in a project to build a paraquat plant for ICI in the Houston, Texas area when the ban on paraquat occurred. The plant had just been completed, and ICI had to convert it to producing an alternate chemical. Paraquat is nasty stuff to deal with, with severe respiratory and skin contact reactions. DDT is mild in comparison.
Following the links back from this blog entry, even some comments links back I found this news video report about an apparently spectacular program by the Chinese. It seem a little dated but may be of interest. Good luck.
http://www.sbs.com.au/dateline/story/watch/id/600026/n/The-Last-Bite