A vaccine to protect healthy adults from malaria[1] was found to be safe and effective in an early-stage clinical trial.


The results of the phase-1 trial on the PfSPZ vaccine are published in the journal Science[2] .


"The global burden of malaria is extraordinary and unacceptable," Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases, said in a statement. "Scientists and health care providers have made significant gains in characterizing, treating and preventing malaria; however, a vaccine has remained an elusive goal. We are encouraged by this important step forward[3] ."


Malaria was the cause of 655,000 deaths around the world[4] in 2010, with most of these deaths occurring in the African region, according to the Centers for Disease Control and Prevention. People most highly at risk for infection are those with an already-lowered immunity, such as young children, travelers (who are therefore not exposed and lack immunity) and pregnant women.


The trial of the vaccine, which is made of weakened sporozoites of the malaria-causing parasite Plasmodium falciparum, was conducted by researchers at the NIAID, the Naval Medical Research Center and the Walter Reed Army Institute of Research. It involved 57 healthy adults between ages 18 and 45, none of whom had ever had malaria before.


First, researchers tested the safety of the vaccine. They administered it to 40 of the participants, while the other 17 did not receive the vaccine. Among those who received the vaccine, researchers administered different numbers of doses (anywhere from two to six) at increasing dosages to test the safety of the vaccine. Researchers kept close watch of the participants for the seven days after they received the vaccine; none of them had any bad side effects nor infections from malaria.


Then, researchers evaluated the effectiveness of the vaccine in protecting against malaria. For this, they allowed five mosquitoes to bite the study participants (including those not vaccinated) three weeks after those who were vaccinated received their last installment. The mosquitoes all carried the P. falciparum strain.



The study participants were monitored for a week as outpatients after they were bitten by the mosquitoes. After the week, they went to the NIH Clinical Center so that the researchers could monitor if they developed malaria (and then treat them with anti-malarial drugs if they did develop an infection).


Most (16 out of 17) of those who received the lower dosages of the vaccine went on to develop malaria, as well as nearly all (11 out of 12) of those who weren't vaccinated at all. But, researchers found that higher dosages of the vaccine seemed to offer protection, with only one-fifth of those receiving higher dosages becoming infected.


Now, researchers noted that an important next step is figuring out how to make the vaccine more feasible to deliver, as right now it's only been developed as an intravenous vaccine (where the vaccine has to be delivered directly into a person's vein).


Currently, vector control[5] is the main method of preventing malaria, according to the World Health Organization. This involves using things like insecticidal nets and indoor spraying with insecticides. Antimalarial medications[6] are another way of preventing malaria; with this method, high-risk people, such as pregnant women and children, are administered the medication during high-transmission seasons.



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  • Avoid Dusk And Dawn


    The evening and early morning hours are <a href="http://www.cdc.gov/ncidod/dvbid/westnile/prevention_info.htm" target="_hplink">peak biting times for many mosquito species</a>, according to the CDC, so consider ramping up your protection or staying inside at these times if you can.
    <br><br>
    But, Conlon warns, other species bite during the day, too. "Whenever you're present, you're on the menu," he says.
    <br><br>
    <em>Flickr photo by <a href="http://www.flickr.com/photos/activesteve/5628626857/" target="_hplink">ActiveSteve</a></em>




  • Eat Garlic


    Garlic has long been rumored to ward off mosquitoes, but there isn't much research to back up the claims. However, <a href="http://www.sciencedaily.com/releases/2009/01/090130154901.htm" target="_hplink">garlic does have some healthy benefits</a>, thanks to the powerful antioxidant allicin that gives it its smell and flavor. Adding a little extra garlic to your summer diet certainly won't hurt!
    <br><br>
    Pure garlic oil, on the other hand, when rubbed on the skin <em>will</em> repel mosquitos -- for around 20 minutes -- but it will probably repel everyone around you as well, jokes Conlon.
    <br><br>
    There is one ingestible to avoid, however. The <em>New York Times</em> reports that alcohol is just about the <a href="http://www.nytimes.com/2007/07/24/health/24real.html" target="_hplink">only food or beverage proven to have a true effect on mosquitos</a>, and the bad news is it attracts them. A small 2002 study showed that more mosquitoes landed on beer drinkers than tee-totalers.
    <br><br>
    <em>Flickr photo by <a href="http://www.flickr.com/photos/jenorton/2212742541/" target="_hplink">lowjumpingfrog</a></em>




  • Avoid Scented Shampoos, Soaps And Perfumes


    This one is mostly rumor, says Conlon. When they're not feasting on humans, mosquitos obtain some nourishment from plants, so the thinking goes that if you smell like a pretty flower, a bug might mistake you for one, but it's never been proven, he says.




  • Citronella


    A small study from 2002 found that <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa011699#t=articleResults" target="_hplink">citronella-based repellents</a> keep bugs away for about 20 minutes or less.
    <br><br>
    While the plant-based oil is thought to smell bad to mosquitoes, it's not highly unpleasant to humans, so if you feel like it works, there's no reason to stop using it, says Conlon, but there may be a bit of a placebo effect going on, he says.
    <br><br>
    The same study found that other plant-based repellents, like geranium oil, didn't provide lasting protection either. However, protection from <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa011699#t=articleResults" target="_hplink">soybean-oil-based repellents</a> lasted about 90 minutes.
    <br><br>
    <em>Flickr photo by <a href="http://www.flickr.com/photos/elwillo/5021856163/" target="_hplink">Keith Williamson</a></em>




  • Burn A Candle


    Whether you light citronella candles or decorative patio torches, smoke will keep mosquitos at bay, says Conlon.
    <br><br>
    <em>Flickr photo by <a href="http://www.flickr.com/photos/tedsblog/904732/" target="_hplink">TedsBlog</a></em>




  • Cover Up


    The CDC recommends wearing long sleeves, pants, hats and closed-toed shoes instead of sandals to <a href="http://wwwnc.cdc.gov/travel/page/mosquito-tick.htm" target="_hplink">cover exposed skin</a>. In the dead of summer, this might not always be appropriate, but if you have to be outside during dusk or dawn, when temperatures are likely to be cooler, long sleeves may be more practical.
    <br><br>
    "Any exposed skin is 'fair game,'" says Conlon.




  • B Vitamins


    According to the Mayo Clinic, taking a daily dose of <a href="http://www.mayoclinic.com/health/mosquito-bites/DS01075/DSECTION=alternative-medicine" target="_hplink">75 to 150 milligrams of vitamin B-1</a> (thiamin) could slightly change your scent in a way that might keep mosquitoes away, but the research isn't conclusive.
    <br><br>
    <em>Flickr photo by <a href="http://www.flickr.com/photos/seanmichaelragan/6254362902/" target="_hplink">seanmichaelragan</a></em>




  • Eliminate Standing Water


    Any pools or puddles around your home or yard can quickly become mosquito breeding ground. The Mayo Clinic recommends unclogging roof gutters, emptying any kids' pools, changing the water in any bird baths weekly, making sure rain is not accumulating in trash can lids and storing flower pots or any other unused containers upside down, <a href="http://www.mayoclinic.com/health/mosquito-bites/ds01075/dsection=prevention" target="_hplink">among other tips you can see here</a>.
    <br><br>
    <em>Flickr photo by <a href="http://www.flickr.com/photos/elias_daniel/281970867/" target="_hplink">elias_daniel</a></em>




  • Stay Close To The Fan


    "Mosquitoes are bad fliers," <a href="http://www.cleveland.com/insideout/index.ssf/2010/06/preventing_mosquito_bites_so_b.html" target="_hplink">Dave Shetlar, an Ohio State University professor of urban landscape entomology</a> told Cleveland.com. Perch yourself near ceiling fans on patios, porches or open-air restaurants that have them.
    <br><br>
    <em>Flickr photo by <a href="http://www.flickr.com/photos/lipstickproject/4637258947/" target="_hplink">JMacPherson</a></em>




  • Ditch The Bug Zapper


    These electronic gadgets will wind up killing bigger bugs, like moths, rather than mosquitoes, says Conlon.
    <br><br>
    In fact, an entomology professor from the University of Delaware published a study in 1996 showing that out of nearly 14,000 insects killed by six zappers in one summer, <a href="http://www.popularmechanics.com/home/improvement/4323044" target="_hplink">only 31 were biting fliers</a>, <em>Popular Mechanics</em> reported. Another 2,000 were beneficial bugs that keep real pests at bay, and the others were harmless species.
    <br><br>
    Plus, mosquitoes are <a href="http://www.cleveland.com/insideout/index.ssf/2010/06/preventing_mosquito_bites_so_b.html" target="_hplink">attracted to <em>dim</em> light</a>, so they may fly toward the zapper initially, but they'll likely turn away from the thing when they get too close, according to Cleveland.com.
    <br><br>
    <em>Flickr photo by <a href="http://www.flickr.com/photos/hfb/182343058/" target="_hplink">hfb</a></em>




  • Lemon Eucalyptus Oil


    The CDC, <em>Consumer Reports</em> and other outlets recommend this "very good repellent" Conlon says, which, at 40 percent concentration will ward off mosquitoes and ticks.
    <br><br>
    However, it isn't recommended for <a href="http://www.consumerreports.org/health/healthy-living/beauty-personal-care/insect-repellent/overview/index.htm" target="_hplink">children under 3</a>, according to <em>Consumer Reports</em>. Conlon explains that isn't necessarily because of toxicity, however. "I think they probably haven't taken the time to get the [EPA] registration," he says, a timely and costly process, when children under 3 can be protected in other ways, like dressing them appropriately, he says.
    <br><br>
    <em>Flickr photo by <a href="http://www.flickr.com/photos/fairfaxcounty/7352235208/" target="_hplink">fairfaxcounty</a></em>




  • Catnip Oil


    According to a 2001 study, this natural repellent is <a href="http://www.sciencedaily.com/releases/2001/08/010828075659.htm" target="_hplink">10 times more effective than DEET</a>. Since then, scientists have been studying its repellency, and Dow Chemical is in the process of getting EPA registration for a new catnip-based product, says Conlon. Of course, every consumer will have to weigh the cost and the benefits, he jokes. You'll repel mosquitoes wearing the stuff, but you're likely to attract cats!
    <br><br>
    <em>Flickr photo by <a href="http://www.flickr.com/photos/cygnus921/2598483750/" target="_hplink">cygnus921</a>
    </em>




  • IR3535


    This cryptically-named repellent, most well-known as the active ingredient in Avon Skin So Soft, is characterized by the EPA as a "biopesticide repellent," meaning it is in fact derived from natural materials. However, the same 2002 study found this compound <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa011699#t=articleResults" target="_hplink">protects against mosquitoes for only about 23 minutes</a>.
    <br><br>
    <em>Photo from <a href="http://www.amazon.com/Avon-Guard-IR3535-EXPEDITION-Spray/dp/B00199RQ5S/ref=sr_1_1?s=hpc&ie=UTF8&qid=1339188213&sr=1-1" target="_hplink">Amazon.com</a></em>




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