Article[edit]

Another intresting article: http://www.liveleak.com/view?i=b29_1212592557 —Preceding unsigned comment added by 81.246.137.55 (talk) 13:22, 13 December 2008 (UTC)[reply]

Moved from main article[edit]

It has been generally accepted that it is impractical to provide at-risk individuals with this vaccination strategy, but that has been recently challenged with work being done by Dr. Stephen Hoffman, one of the key researchers who originally sequenced the genome of Plasmodium falciparum. His work most recently has revolved around solving the logistical problem of isolating and preparing the parasites equivalent to 1000 irradiated mosquitoes for mass storage and inoculation of human beings. The company has recently received several multi-million dollar grants from the Bill & Melinda Gates Foundation and the U.S. government to begin early clinical studies in 2007 and 2008.[1] The Seattle Biomedical Research Institute (SBRI), funded by the Malaria Vaccine Initiative, assures potential volunteers that "the [2009] clinical trials won't be a life-threatening experience. While many volunteers [in Seattle] will actually contract malaria, the cloned strain used in the experiments can be quickly cured, and does not cause a recurring form of the disease. Some participants will get experimental drugs or vaccines, while others will get placebo."[2]

Instead, much work has been performed to try and understand the immunological processes that provide protection after immunization with irradiated sporozoites. After the mouse vaccination study in 1967,[3] it was hypothesized that the injected sporozoites themselves were being recognized by the immune system, which was in turn creating antibodies against the parasite. It was determined that the immune system was creating antibodies against the circumsporozoite protein (CSP) which coated the sporozoite.[4] Moreover, antibodies against CSP prevented the sporozoite from invading hepatocytes.[5] CSP was therefore chosen as the most promising protein on which to develop a vaccine against the malaria sporozoite. It is for these historical reasons that vaccines based on CSP are the most numerous of all malaria vaccines.

Presently, there is a huge variety of vaccine candidates on the table. Pre-erythrocytic vaccines (vaccines that target the parasite before it reaches the blood), in particular vaccines based on CSP, make up the largest group of research for the malaria vaccine. There have been recent breakthroughs in vaccines that seek to avoid more severe pathologies of malaria by preventing adherence of the parasite to blood venules and placenta, but financing is not yet in place for trials.[6] Other potential vaccines include those that seek to induce immunity to the blood stages of the infection and transmission-blocking vaccines that would stop the development of the parasite in the mosquito right after the mosquito has taken a bloodmeal from an infected person.[7] It is hoped that the knowledge of the P. falciparum genome, the sequencing of which was completed in 2002,[8] will provide targets for new drugs or vaccines.[9]

The first vaccine developed that has undergone field trials, is the SPf66, developed by Manuel Elkin Patarroyo in 1987. It presents a combination of antigens from the sporozoite (using CS repeats) and merozoite parasites. During phase I trials a 75% efficacy rate was demonstrated and the vaccine appeared to be well tolerated by subjects and immunogenic. The phase IIb and III trials were less promising, with the efficacy falling to between 38.8% and 60.2%. A trial was carried out in Tanzania in 1993 demonstrating the efficacy to be 31% after a years follow up, however the most recent (though controversial) study in The Gambia did not show any effect. Despite the relatively long trial periods and the number of studies carried out, it is still not known how the SPf66 vaccine confers immunity; it therefore remains an unlikely solution to malaria. The CSP was the next vaccine developed that initially appeared promising enough to undergo trials. It is also based on the circumsporoziote protein, but additionally has the recombinant (Asn-Ala-Pro15Asn-Val-Asp-Pro)2-Leu-Arg(R32LR) protein covalently bound to a purified Pseudomonas aeruginosa toxin (A9). However at an early stage a complete lack of protective immunity was demonstrated in those inoculated. The study group used in Kenya had an 82% incidence of parasitaemia whilst the control group only had an 89% incidence. The vaccine intended to cause an increased T-lymphocyte response in those exposed, this was also not observed.

The efficacy of Patarroyo's vaccine has been disputed with some US scientists concluding in The Lancet (1997) that "the vaccine was not effective and should be dropped" while the Colombian accused them of "arrogance" putting down their assertions to the fact that he came from a developing country.

The RTS,S/AS02A vaccine is the candidate furthest along in vaccine trials. It is being developed by a partnership between the PATH Malaria Vaccine Initiative (a grantee of the Gates Foundation), the pharmaceutical company, GlaxoSmithKline, and the Walter Reed Army Institute of Research.[10] In the vaccine, a portion of CSP has been fused to the immunogenic "S antigen" of the hepatitis B virus; this recombinant protein is injected alongside the potent AS02A adjuvant.[7] In October 2004, the RTS,S/AS02A researchers announced results of a Phase IIb trial, indicating the vaccine reduced infection risk by approximately 30% and severity of infection by over 50%. The study looked at over 2,000 Mozambican children.[11] More recent testing of the RTS,S/AS02A vaccine has focused on the safety and efficacy of administering it earlier in infancy: In October 2007, the researchers announced results of a phase I/IIb trial conducted on 214 Mozambican infants between the ages of 10 and 18 months in which the full three-dose course of the vaccine led to a 62% reduction of infection with no serious side-effects save some pain at the point of injection.[12] Further research will delay this vaccine from commercial release until around 2011.[13]

On 6 April 2010, Crucell, a Dutch biopharmaceutical company, has signed a binding letter of agreement with GlaxoSmithKline Biologicals (GSK) to collaborate on developing malaria vaccine candidate.

Doc James (talk · contribs · email) 11:09, 20 December 2010 (UTC) [reply]

References

  1. ^ Sanaria Press and Publications
  2. ^ Doughton, Sandi (2008-03-05). "You can get paid to catch malaria". The Seattle Times.
  3. ^ Cite error: The named reference Nussenzweig1967 was invoked but never defined (see the help page).
  4. ^ Zavala F, Cochrane A, Nardin E, Nussenzweig R, Nussenzweig V (1983). "Circumsporozoite proteins of malaria parasites contain a single immunodominant region with two or more identical epitopes". J Exp Med. 157 (6): 1947–57. doi:10.1084/jem.157.6.1947. PMC 2187031. PMID 6189951.((cite journal)): CS1 maint: multiple names: authors list (link)
  5. ^ Hollingdale M, Nardin E, Tharavanij S, Schwartz A, Nussenzweig R (1984). "Inhibition of entry of Plasmodium falciparum and P. vivax sporozoites into cultured cells; an in vitro assay of protective antibodies". J Immunol. 132 (2): 909–13. PMID 6317752.((cite journal)): CS1 maint: multiple names: authors list (link)
  6. ^ Andersen, Morten (2010-04-25). "Kamp mod malaria før fødslen". Politiken (in Danish). p. Science section, p. 3.
  7. ^ a b Matuschewski K (2006). "Vaccine development against malaria". Curr Opin Immunol. 18 (4): 449–57. doi:10.1016/j.coi.2006.05.004. PMID 16765576.
  8. ^ Gardner MJ, Hall N, Fung E; et al. (2002). "Genome sequence of the human malaria parasite Plasmodium falciparum". Nature. 419 (6906): 498–511. doi:10.1038/nature01097. PMID 12368864. ((cite journal)): Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  9. ^ Gardner M, Hall N, Fung E; et al. (2002). "Genome sequence of the human malaria parasite Plasmodium falciparum". Nature. 370 (6906): 1543. doi:10.1038/nature01097. PMID 12368864. ((cite journal)): Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link)
  10. ^ Heppner DG, Kester KE, Ockenhouse CF; et al. (2005). "Towards an RTS,S-based, multi-stage, multi-antigen vaccine against falciparum malaria: progress at the Walter Reed Army Institute of Research". Vaccine. 23 (17–18): 2243–50. doi:10.1016/j.vaccine.2005.01.142. PMID 15755604. ((cite journal)): Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link)
  11. ^ Alonso PL, Sacarlal J, Aponte JJ; et al. (2004). "Efficacy of the RTS,S/AS02A vaccine against Plasmodium falciparum infection and disease in young African children: randomised controlled trial". Lancet. 364 (9443): 1411–20. doi:10.1016/S0140-6736(04)17223-1. PMID 15488216. ((cite journal)): Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link)
  12. ^ Aponte JJ, Aide P, Renom M; et al. (2007). "Safety of the RTS,S/AS02D candidate malaria vaccine in infants living in a highly endemic area of Mozambique: a double blind randomised controlled phase I/IIb trial". Lancet. 370 (9598): 1543–51. doi:10.1016/S0140-6736(07)61542-6. PMID 17949807. ((cite journal)): Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  13. ^ Africa: Malaria - Vaccine Expected in 2011. Accra Mail. 9 January 2007. Retrieved 15 January 2007.

Meaning of "Abs"[edit]

I'm guessing that the numerous bullet points in the subsection Potential targets of a vaccine which start with "Abs that ..." actually reference "A(nti)b(odie)s". Is that right?

There is no help to be found on the Abs page of Wikipedia, so I'm guessing it's not a standard abbreviation except perhaps in pharmacology (or whatever term best describes "the science of developing vaccines").

yoyo (talk) 14:24, 5 August 2012 (UTC)[reply]

Candidate[edit]

This article is rather hard to parse, but I think [1] is not yet mentioned as a candidate. -- Beland (talk) 19:06, 19 August 2013 (UTC)[reply]

The related scientific article in Science is available under doi:10.1126/science.1241800. --Svencb (talk) 21:42, 7 February 2014 (UTC)[reply]

WRAIR's "quadvax" vaccine[edit]

Perhaps it should be mentioned that the WRAIR (Walter Reed Army Institute of Research) "quadvax" vaccine seems to be able to work against many types of malaria, see here 109.130.234.144 (talk) 13:53, 16 February 2014 (UTC)[reply]

== 1st malaria vaccine: GlaxoSmithKlein & partner Agenus, Inc.'s filing accepted by EMA 

On 7-24-14, partners GlaxoSmithKlein (GSK) and Agenus Inc. (AGEN) had their request for
review of the first malaria vaccine candidate accepted by the European Medicines Agency.

Agenus Inc.'s QS-21 Stimulon adjuvant is included as booster in the GSK malaria vaccine formulation, which was in development for about 30 years, with the help of recent funding 

from the Bill and Melinda Gates Foundation.   Further details may found at:

http://www.bloomberg.com/news/2014-07-24/glaxo-seeks-approval-for-world-s-

first-malaria-vaccine.html

and also at : http://finance.yahoo.com/news/first-vaccine-candidate-malaria-accepted-100100416.html 

 74.76.227.152 (talk) 20:16,
17 October 2014 (UTC)

Source <Bloomberg.com/news> 74.76.227.152 (talk) 22:09, 17 October 2014 (UTC)[reply]

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Interesting new development?[edit]

First vaccine to fully immunize against malaria builds on pandemic-driven RNA tech, The Academic Times. I have no idea if this is enough to add something to the article, and neither my scientific competence nor my English level allow me to interven in the article directly. 2A02:A03F:6129:CF00:31E8:C045:BDE7:F6FB (talk) 08:21, 28 February 2021 (UTC)[reply]

I added a section on that titled "saRNA vaccine against PMIF" as it does not seem to have a recognised name yet. Tim333 (talk) 10:43, 28 February 2021 (UTC)[reply]

Merge RTS,S into this article?[edit]

NOT MERGED
Strong consensus to not merge these articles. Remagoxer (talk) 17:36, 4 May 2022 (UTC)[reply]

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

It seems like RTS,S was tagged with a merger template directing here. Should we go ahead with this? (Personally, I think the two subjects are sufficiently distinct to warrant remaining separate but still.) Pinging @Whywhenwhohow, who tagged the other article. Remagoxer (talk) 18:36, 8 October 2021 (UTC)[reply]

(To elaborate on my point - while RTS,S is currently the only approved vaccine, several other vaccines (including an enchanced version of RTS,S) are under development/have been looked into. RTS,S is also quite clearly notable.) Remagoxer (talk) 18:41, 8 October 2021 (UTC)[reply]
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

'Plasmodium is a genus; Plasmodium falciparum is a species[edit]

Article currently reads -

The Plasmodium species has a very high rate of replication, much higher than that actually needed to ensure transmission in the parasite's lifecycle

.

- Plasmodium is a genus; Plasmodium falciparum is a species within the genus Plasmodium.

and

- The source cited for this section doesn't seem to have the info about the notably high rate of replication.

.

So [A] We should give a better cite for this info.

[B] We should clarify whether we're saying that all Plasmodium show this high rate of replication, or only the species Plasmodium falciparum.

- 177.43.7.195 (talk) 00:10, 19 April 2023 (UTC)[reply]

R21 promotion[edit]

This reads in part like it was written by Oxford/Serum Institute. Phase III results are not yet public, so it's impossible to say that the vaccine is the most effective yet. Needs a rewrite for objectivity. 92.106.201.128 (talk) 16:41, 26 April 2023 (UTC)[reply]

A phase III trial with 4,800 children across four African countries was reported in November 2022, demonstrating vaccine efficacy of 74% against a severe malaria episode.
Yes, your claim needs a rewrite for objectivity.--Julius Senegal (talk) 17:53, 26 April 2023 (UTC)[reply]

Sterilizing immunity?[edit]

why was my edit removed ? Malaria vaccination does not provide sterilizing immunity? Or am I mistaken? Ansgarjohn (talk) 11:14, 23 January 2024 (UTC)[reply]

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