Editing Malaria (section)

=== Research on malaria vaccines ===
{{main|Malaria vaccine}}

[[Malaria vaccine]]s have been another goal of research. The first promising studies demonstrating the potential for a malaria vaccine were performed in 1967 by immunising mice with live, radiation-[[Attenuator (genetics)|attenuated]] sporozoites, which provided significant protection to the mice upon subsequent injection with normal, viable sporozoites. Since the 1970s, there has been considerable progress in developing similar vaccination strategies for humans.<ref name="Vanderberg-2009" />

In 2013, WHO and the malaria vaccine funders group set a goal to develop vaccines designed to interrupt malaria transmission with malaria eradication's long-term goal.<ref>{{cite web |title=World Malaria Report 2013 |url=https://www.who.int/entity/malaria/publications/world_malaria_report_2013/wmr2013_no_profiles.pdf?ua=1 |access-date=13 February 2014 |publisher=World Health Organization |format=PDF}}</ref> The first vaccine, called [[RTS,S]], was approved by European regulators in 2015.<ref name="Walsh-2015" /> As of 2023, two [[malaria vaccine]]s have been licensed for use.<ref name="WHO recommends R21-2023"/> Other approaches to combat malaria may require investing more in research and greater primary health care.{{sfn|WHO|2020|p={{page needed|date=July 2024}}}} Continuing surveillance will also be important to prevent the return of malaria in countries where the disease has been eliminated.<ref>{{cite journal | vauthors = Mendis K | title = Eliminating malaria should not be the end of vigilance | journal = Nature | volume = 573 | issue = 7772 | pages = 7 | date = September 2019 | pmid = 31485061 | doi = 10.1038/d41586-019-02598-1 | bibcode = 2019Natur.573....7M | doi-access = free }}</ref>

As of 2019 it is undergoing pilot trials in 3 sub-Saharan African countries—Ghana, Kenya and Malawi—as part of the WHO's Malaria Vaccine Implementation Programme (MVIP).<ref>{{cite web |author=World Health Organization |date=March 2020 |title=Q&A on the malaria vaccine implementation programme (MVIP) |url=https://www.who.int/malaria/media/malaria-vaccine-implementation-qa/en/ |access-date=6 May 2020 |publisher=WHO |archive-date=13 May 2020 |archive-url=https://web.archive.org/web/20200513074401/https://www.who.int/malaria/media/malaria-vaccine-implementation-qa/en/ |url-status=live }}</ref>
 
Immunity (or, more accurately, [[immune tolerance|tolerance]]) to ''P.&nbsp;falciparum'' malaria does occur naturally, but only in response to years of repeated infection.<ref name="Tran-2012" /><ref>{{cite journal | vauthors = Abuga KM, Jones-Warner W, Hafalla JC | title = Immune responses to malaria pre-erythrocytic stages: Implications for vaccine development | journal = Parasite Immunology | volume = 43 | issue = 2 | pages = e12795 | date = February 2021 | pmid = 32981095 | pmc = 7612353 | doi = 10.1111/pim.12795 }}</ref> An individual can be protected from a ''P.&nbsp;falciparum'' infection if they receive about a thousand bites from mosquitoes that carry a version of the parasite rendered non-infective by a dose of [[X-ray]] [[irradiation]].<ref name="Hill-2011" /> The highly [[polymorphism (biology)|polymorphic]] nature of many ''P.&nbsp;falciparum'' proteins results in significant challenges to vaccine design. Vaccine candidates that target antigens on gametes, zygotes, or ookinetes in the mosquito midgut aim to block the transmission of malaria. These transmission-blocking vaccines induce [[antibodies]] in the human blood; when a mosquito takes a blood meal from a protected individual, these antibodies prevent the parasite from completing its development in the mosquito.<ref name="Crompton-2010" /> Other vaccine candidates, targeting the blood-stage of the parasite's life cycle, have been inadequate on their own.<ref name="Graves-2006b" /> For example, [[Manuel Elkin Patarroyo|SPf66]] was tested extensively in areas where the disease was common in the 1990s, but trials showed it to be insufficiently effective.<ref name="Graves-2006a" />

As of 2020, the RTS,S vaccine has been shown to reduce the risk of malaria by about 40% in children in Africa.<ref name="www.who.int-3" /><ref name="WHO PP-2016">{{cite journal | vauthors =  | title = Malaria vaccine: WHO position paper-January 2016 | journal = Relevé Épidémiologique Hebdomadaire | volume = 91 | issue = 4 | pages = 33–51 | date = January 2016 | pmid = 26829826 | url = https://www.who.int/wer/2016/wer9104.pdf?ua=1 | archive-url = https://web.archive.org/web/20200423102942/http://www.who.int/wer/2016/wer9104.pdf?ua=1 | archive-date = 2020-04-23 }}</ref> A preprint study of the R21 vaccine has shown 77% vaccine efficacy.{{update inline|date=June 2022}}<ref>{{cite journal | vauthors = Datoo MS, Natama MH, Somé A, Traoré O, Rouamba T, Bellamy D, Yameogo P, Valia D, Tegneri M, Ouedraogo F, Soma R, Sawadogo S, Sorgho F, Derra K, Rouamba E, Orindi B, Ramos Lopez F, Flaxman A, Cappuccini F, Kailath R, Elias S, Mukhopadhyay E, Noe A, Cairns M, Lawrie A, Roberts R, Valéa I, Sorgho H, Williams N, Glenn G, Fries L, Reimer J, Ewer KJ, Shaligram U, Hill AV, Tinto H | title = Efficacy of a low-dose candidate malaria vaccine, R21 in adjuvant Matrix-M, with seasonal administration to children in Burkina Faso: a randomised controlled trial | journal = The Lancet | volume = 397 | issue = 10287 | pages = 1809–1818 | date = May 2021 | pmid = 33964223 | pmc = 8121760 | doi = 10.1016/S0140-6736(21)00943-0 | ssrn = 3830681 }}</ref>

In 2021, researchers from the [[University of Oxford]] reported findings from a [[Phases of clinical research|Phase IIb trial]] of a candidate malaria vaccine, R21/Matrix-M, which demonstrated efficacy of 77% over 12-months of follow-up. This vaccine is the first to meet the [[World Health Organization]]'s Malaria Vaccine Technology Roadmap goal of a vaccine with at least 75% efficacy.<ref>[https://www.eurekalert.org/pub_releases/2021-04/uoo-mvb042221.php Malaria vaccine becomes first to achieve WHO-specified 75% efficacy goal] {{Webarchive|url=https://web.archive.org/web/20210423111503/https://www.eurekalert.org/pub_releases/2021-04/uoo-mvb042221.php |date=2021-04-23 }}, News Release 23 April 2021, [[University of Oxford]]</ref>

Germany-based BioNTECH SE is developing an mRNA-based malaria vaccine BNT165<ref>{{cite web |title=Home |url=https://www.biontech.com/int/en/home.html |access-date=2023-08-03 |archive-date=2023-08-03 |archive-url=https://web.archive.org/web/20230803135340/https://www.biontech.com/int/en/home.html |url-status=live }}</ref> which has recently initiated a Phase 1 study [clinicaltrials.gov identifier: NCT05581641] in December 2022. The vaccine, based on the circumsporozoite protein (CSP) is being tested in adults aged 18–55 yrs at 3 dose levels to select a safe and tolerable dose of a three-dose schedule. Unlike GSK's RTS,S (AS01) and Serum Institute of India's R21/MatrixM, BNT-165 is being studied in adult age groups meaning it could be developed for Western travelers as well as those living in endemic countries. For the travelers profile, a recent commercial assessment forecast potential gross revenues of BNT-165 at $479m (2030) 5-yrs post launch, POS-adjusted revenues.<ref>{{cite web |title=VacZine Analytics &#124; Our products - MarketVIEW: Travel vaccines segment report |url=https://www.vaczine-analytics.com/products-marketviewVAMV090_travel_vaccines_segment_report.asp |access-date=2023-08-03 |archive-date=2023-08-03 |archive-url=https://web.archive.org/web/20230803135344/https://www.vaczine-analytics.com/products-marketviewVAMV090_travel_vaccines_segment_report.asp |url-status=live }}</ref>