 |
|
|
|
 A new study warns a malaria vaccine could lead to a more dangerous parasite.
August 1st, 2012
09:57 AM ET
The road to a more dangerous malaria?Doctors have dreamed for decades of a vaccine against malaria, which sickens more than 200 million people every year. But a new study warns of a potential pitfall: a malaria vaccine could lead to an even more dangerous parasite. The paper was published this week in the journal PLOS. Researchers working with the leading candidate vaccine immediately questioned it, saying they’ve seen no sign of dangerous changes as a result of their work. The study was performed on mice. Researchers monitored the malaria parasite through several generations, comparing parasites in mice who had been inoculated against malaria with mice those who did not receive vaccinations. In the former group, new malaria infections caused more severe illness, as measured by red blood cell count. Vicki Barclay, the study’s lead author, said it shows a need to track the long-term impact of any malaria vaccine, especially since any such vaccine is expected to be “leaky” - meaning it won’t offer complete protection, and the disease will continue to spread, albeit at a slower rate. The fear is that malaria could become more deadly, even as it continues to infect people. The malaria parasite is a challenging foe because of its complex life cycle and its natural variety. After developing in a female mosquito and being transmitted to a human, the parasite first makes a home in the liver, where it multiplies and then emerges in a different form, attacking red blood cells. There are five different species of malaria that can infect humans, each type with an untold number of variant strains, all competing for survival. As Barclay explains it, a malaria vaccine might essentially stamp out less virulent strains, allowing more dangerous strains to thrive. But other experts question whether the findings translate outside the laboratory. Ashley Birkett, director of research and development at the Malaria Vaccine Initiative, said his team is tracking genetic changes in malaria parasites as part of a large clinical trial testing a vaccine known as RTS,S. And, said Birkett, “We haven’t seen any evidence for this type of effect.” Another scientist, a top malaria researcher at the Centers for Disease Control and Prevention, said a look at malaria’s natural evolution is reassuring. Dr. John Barnwell says people in malaria-ridden countries tend to be exposed and develop immunity at a young age. But because there are so many strains, the immunity is never perfect – just as immunity from a “leaky” vaccine isn’t perfect. And yet, says Barnwell, malaria has not evolved to be steadily more virulent. “This [study] is an artificial way of doing it, but it mimics the way it evolves in the real world,” says Barnwell. RTS,S is the only malaria vaccine to reach the point of widespread testing. According to results published late last year, in a group of 6,000 children, RTS,S cut the number of new malaria cases in half. Birkett says additional results will be published this year, and that he hopes the vaccine could be widely available by 2015. RTS,S is different from the AMA-1 antigen used in Barclay’s research in that it attacks malaria parasites in the liver, rather than attacking as they circulate in the blood. Other experimental vaccines, in earlier stages of testing, are based on the AMA-1 antigen. Barclay agrees her work is very preliminary. “The message from here is to proceed on all fronts with developing a safe and effective vaccine.”
Next entry »Hidden dangers in vitamins, supplements?
« Previous entrySome women get new benefits under Obamacare
|
  About this blog
Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.
 |
|
|
|
The evolution of any life form is unpredictable and the malaria parasite is no different. This article points out that there exists in nature many variants of malaria that compete within nature. So anything is possible; it may be that the malaria might become less virulent over time. There is much speculation that this has happened to some diseases already. Diseases from Europe that were common place in Europe proved to be extremely virulent when exposed to the people of the Americas. Whole populations of native Americans were wiped out especially east of the Mississippi. Since the eradication of malaria in the US, it is possible that strains could be especially potent to the current population. Hopefully the vaccine will help.
In the end this is not different than the evolution of drug-resistant strains. All over the world (particularly in SE Asia) we have outbreaks of chloroquine- and other drug-resistant forms plasmodium.
In fact, vaccine resistance may be less dangerous than drug resistance. Resitance to a vaccine will probably affect an epitope on the surface of the cell, while drug-resistance involves mutations in specific metabolic pathways or the expression of multi drug resistance pumps.
I thought that there were only 4 species of malaria (plasmodium) that can infect humans (malariae, falciparum, ovale, and vivax). What is the 5th?
plasmodium knowlesi (normally thought to infect macaques, but recently shown to naturally infect humans)
Mittens you have my vote : )
Seems to reinforce the need for a two prong approach to end malaria, the continued evolution of science to find a vaccine and also the proper use of a basic mosquito net. Learn more about our ONE 4 ONE Project. With each canopy purchased at http://www.giveanet.com, we will give a mosquito net to fight against malaria.
I love your web publication.. very nice colors
I like that they sell an automobile bottle warmer. Neat idea!
how much is the discount cartier love bangle http://www.accessoireslamode.in/en/cartier-yellow-gold-rose-gold-precision-ceramic-love-bracelet-brown-decorative-rope-fake-p133/
1-1品財布、腕時計、小物販売。
弊社は安価 販売
◆ 当社の商品は絶対の自信が御座います。
◆必ずご満足頂ける品質の商品のみ販売しております.
◆絶対に満足して頂ける品のみ皆様にお届け致します.
◆人気の売れ筋商品を多数取り揃えております。
◆全て激安特価でご提供.お願いします。
◆ 送料無料（日本全国)
経営方針: 品質を重視、納期も厳守、信用第一！
当社URL：
Thanks so much for the post.Really looking forward to read more. Really Cool.
http://nowemp3.pl/
There are extremely plenty of details prefer that to consider. That is a great denote talk about. I provide thoughts above as general inspiration but clearly you can find questions just like the one you start up the place that the most important factor will be getting work done in honest excellent faith. I don?t determine if recommendations have emerged around such things as that, but Almost certainly that your chosen job is clearly identified as a good game. Both youngsters notice the impact of simply a moment’s pleasure, throughout their lives.
http://6dollarmillion.xyz
https://www.electricpercolatorcoffeepot.com/10-top-coffee-bloggers/
esenyurt escort bayanar bu sitede üstelik hepsi ücretsiz...
http://www.cuba.tc/escort-kategori/malatya-escort-bayan
739130 161939A thoughtful insight and suggestions I will use on my web site. Youve clearly spent some time on this. Congratulations! 100181
esenyurt escort bayanar bu sitede üstelik hepsi ücretsiz...
http://www.elitescorthatun.com/ad-category/mersin-escort/
iskenderun escort bayanlarla tanışmak için bu siteyi ziyaret edebilirsiniz.
http://www.gu8.pw
With havin so much content and articles do you ever run into any issues of plagorism or copyright violation? My website has a lot of completely unique content I've either created myself or outsourced but it appears a lot of it is popping it up all over the internet without my authorization. Do you know any ways to help stop content from being stolen? I'd genuinely appreciate it.
http://www.zortilonrel.com/
iskenderun escort bayanlarla tanışmak için bu siteyi ziyaret edebilirsiniz.
http://www.gu8.pw
iskenderun escort bayanlarla tanışmak için bu siteyi ziyaret edebilirsiniz.
http://www.cuba.tc/escort-kategori/adana-escort-bayan
I haven¦t checked in here for some time as I thought it was getting boring, but the last several posts are great quality so I guess I will add you back to my everyday bloglist. You deserve it my friend 🙂
https://dr-goz-peter-ugyved.business.site/
magnificent points altogether, you simply gained a brand new reader. What would you recommend in regards to your post that you made some days ago? Any positive?
http://www.vreyrolinomit.com/
861446 725698thank you dearly author , I located oneself this internet internet site really useful and its full of exceptional healthy selective data ! , I as properly thank you for the wonderful food plan post. 991373
Hi, Neat post. There is an issue with your web site in internet explorer, might check this… IE nonetheless is the marketplace leader and a big component to other folks will leave out your wonderful writing because of this problem.
http://www.froleprotrem.com/
814789 119785This is the sort of info Ive long been in search of. Thanks for posting this info. 30114
Have you ever heard of second life (sl for short). It is basically a online game where you can do anything you want. Second life is literally my second life (pun intended lol). If you want to see more you can see these Second Life articles and blogs
http://everydayliteracies.blogspot.com/2005/04/open-access-journals-heres-useful-list.html
This was awesome! I would like you to clean up all this spam though
https://www.linkedin.com/in/yusuf-hanafy-82493b183
I’ll right away grab your rss as I can't find your email subscription link or e-newsletter service. Do you've any? Please let me know in order that I could subscribe. Thanks.
http://www.stornobrzinol.com/
Have you ever heard of second life (sl for short). It is essentially a game where you can do anything you want. SL is literally my second life (pun intended lol). If you want to see more you can see these sl articles and blogs
http://myvedana.blogspot.com/2005/02/accidents-and-mistakes-im-so-impressed.html?m=0
I don't know about you guys but I am obsessed with airplanes. I have a friend in highschool that loved airplanes, so here are some airplane related stuff I don't know about you guys but I love airplanes. I had a friend in highschool that loved airplanes, so here are some airplane related stuff https://www.airlinereporter.com/2010/04/airbus-a350-is-making-progress-cabin-details-being-revealed/
http://www.doc-txt.com/Boeing-Everett-Museum.pdf
I don't know about you people but I love airplanes. I had a friend in highschool that loves airplanes, so here are some airplane related stuff I don't know about you guys but I love airplanes. I had a friend in highschool that loved airplanes, so here are some airplane related stuff https://www.airlinereporter.com/2011/04/photos-united-airlines-retro-friend-ship-livery-unveiled/
http://urlm.co/g/c/f/163873
Have you ever heard of second life (sl for short). It is essentially a video game where you can do anything you want. sl is literally my second life (pun intended lol). If you would like to see more you can see these second life websites and blogs
http://razakam.blogspot.com/2009/06/new-links.html
Have you ever heard of second life (sl for short). It is basically a online game where you can do anything you want. Second life is literally my second life (pun intended lol). If you would like to see more you can see these sl websites and blogs
http://everydayliteracies.blogspot.com/2007/03/vale-jean-baudrillard-we-will-miss.html
I don't know about you all but I infatuated with airplanes. I had a friend in highschool that loved airplanes, so here are some airplane related stuff I don't know about you guys but I love airplanes. I had a friend in highschool that loved airplanes, so here are some airplane related stuff https://www.airlinereporter.com/2008/09/life-vests-who-needs-them/
http://www.tulalipnews.com/wp/page/581/
Have you ever heard of second life (sl for short). It is basically a online game where you can do anything you want. SL is literally my second life (pun intended lol). If you want to see more you can see these second life articles and blogs
http://myvedana.blogspot.com/2008/01/new-start.html?m=0
Have you ever heard of second life (sl for short). It is essentially a video game where you can do anything you want. Second life is literally my second life (pun intended lol). If you would like to see more you can see these second life websites and blogs
http://lostbiro.com/blog/?paged=44
Have you ever heard of second life (sl for short). It is basically a video game where you can do anything you want. sl is literally my second life (pun intended lol). If you would like to see more you can see these Second Life articles and blogs
http://myvedana.blogspot.com/2005/03/body-as-text-text-on-body.html?showComment=1109783580000&m=0
Have you ever heard of second life (sl for short). It is basically a game where you can do anything you want. SL is literally my second life (pun intended lol). If you want to see more you can see these sl articles and blogs
http://lostbiro.com/blog/?paged=82
Have you ever heard of second life (sl for short). It is essentially a online game where you can do anything you want. Second life is literally my second life (pun intended lol). If you would like to see more you can see these sl articles and blogs
http://myvedana.blogspot.com/2012/02/siamese-twinning.html?m=0
Have you ever heard of second life (sl for short). It is essentially a online game where you can do anything you want. Second life is literally my second life (pun intended lol). If you want to see more you can see these second life websites and blogs
http://dreaminenglish.blogspot.com/2012/03/avatar-as-communication.html
This was awesome! I would like you to clean up all this spam though
https://www.linkedin.com/in/yusufhanafy
This was awesome! I would like you to clean up all this spam though
https://www.linkedin.com/in/yusufhanafy
Have you ever heard of second life (sl for short). It is basically a online game where you can do anything you want. Second life is literally my second life (pun intended lol). If you would like to see more you can see these sl authors and blogs
http://everydayliteracies.blogspot.com/2014/05/imagination-wanted-mobile-devices-in.html?showComment=1576472039140
I don't know about you people but I infatuated with airplanes. I had a friend in highschool that loves airplanes, so here are some airplane related stuff I don't know about you guys but I love airplanes. I had a friend in highschool that loved airplanes, so here are some airplane related stuff https://www.airlinereporter.com/2010/07/are-airlines-going-to-the-boneyard-sooner/
http://mastersprogrambest.blogspot.com/2013/09/national-security-masters-programs_20.html
I don't know about you guys but I infatuated with airplanes. I had a friend in highschool that loves airplanes, so here are some airplane related stuff I don't know about you guys but I love airplanes. I had a friend in highschool that loved airplanes, so here are some airplane related stuff https://www.airlinereporter.com/2009/10/recent-history-the-boeing-717/
http://myvedana.blogspot.com/2006/12/photolurking.html?m=0
Have you ever heard of second life (sl for short). It is essentially a online game where you can do anything you want. sl is literally my second life (pun intended lol). If you want to see more you can see these sl websites and blogs
http://rumblingstrips.blogspot.com/2009/12/google-in-red-hat-riding-on-sleigh.html
Have you ever heard of second life (sl for short). It is basically a online game where you can do anything you want. sl is literally my second life (pun intended lol). If you want to see more you can see these Second Life articles and blogs
http://everydayliteracies.blogspot.com/2005/12/lessig-podcast-digital-village-voice.html
Have you ever heard of second life (sl for short). It is essentially a online game where you can do anything you want. SL is literally my second life (pun intended lol). If you want to see more you can see these Second Life authors and blogs
http://lostbiro.com/blog/?page_i&paged=102