Despite significant progress fighting malaria over the past few decades, the disease still kills around 600,000 people annually. Malaria is a leading cause of death globally, especially for young children in Africa, who make up around 70% of all malaria deaths worldwide.¹See the WHO fact sheet on malaria, which states “Globally in 2024, there were an estimated 282 million malaria cases and 610 000 malaria deaths in 80 countries…the WHO African Region was home to 95% of malaria cases (265 million) and 95% (579,000) of malaria deaths. Children under 5 accounted for about 75% of all malaria deaths in the Region.” 75% * 95% = 71%.

While malaria prevention has long been a focus for GiveWell, the growing capacity and specialized expertise on our malaria team are allowing us to take on this challenge now in a way that would not have been possible even a few years ago.

Over our nineteen-year history, GiveWell has directed more than $1 billion in donations to malaria prevention programs that we estimate will save more than 235,000 lives. This is primarily through two core programs:²As other prevention programs have emerged, such as malaria vaccines, we have also supported them when we estimated that doing so would be highly cost-effective.

• Seasonal malaria chemoprevention (SMC), which provides preventive antimalarial medication to young children during the months when malaria is mostly likely to be transmitted. We have directed more than $500 million to support SMC, most via Malaria Consortium’s SMC program, one of our Top Charities.
• Insecticide-treated nets, which are typically hung over beds or other sleeping spaces to provide protection from mosquitoes at night. We have directed more than $600 million to support net campaigns, most via Against Malaria Foundation, another of our Top Charities.

GiveWell’s overall research team has doubled in size over the past few years. Our malaria research team is the largest of our research teams, with 15 people collectively devoting more than 20,000 hours each year to our expanded efforts.³We expect each research staff member contributes about 1,840 hours per year, accounting for holidays and time off, about 75% of which is spent on research work (1840 x 15 x 0.75 = 20,700). For more on how we calculate research hours per person, see here.

With this growth, we are working to reduce malaria deaths even further by (1) funding evidence to improve our future grantmaking decisions for core malaria prevention programs, (2) identifying ways to increase coverage of our core programs, and (3) expanding our portfolio beyond our core programs.

Funding Evidence to Improve Future Grantmaking Decisions

GiveWell’s primary focus has always been researching, identifying, and directing donations to programs we believe will do the most good. That work requires understanding the impact of the programs we support as well as we can by collecting information about them. This is particularly important when making decisions about how to allocate large amounts of funding, as in the case of SMC and nets. Our efforts to gather stronger data and evidence on malaria prevention strategies have focused on funding new studies, as well as strengthening monitoring and evaluation data for the programs we already fund.

We have funded several grants to collect information that will allow us to resolve some of our uncertainties and refine our cost-effectiveness estimates. For example, we funded household surveys in Democratic Republic of the Congo to collect data on the prevalence of malaria infections, net durability, and the proportion of people likely to use nets without a nets campaign. We expect this will help us make better decisions if we decide to fund additional nets campaigns in the country.

Since there is limited evidence about how long insecticide-treated nets—particularly new types of nets that use two insecticides—provide protection, we also funded studies in Nigeria and Cameroon to assess how long the insecticide in the nets is effective at killing and repelling mosquitoes, as well as how long nets maintain their physical integrity. This will help us refine our estimate of how long nets provide protection, which will improve our estimates of nets’ impact and might inform how often we will consider funding campaigns.

We have also been working to support monitoring and evaluation efforts. The rest of this section takes a closer look at one example: We recently funded IDinsight and the Institut de Recherche en Sciences de la Santé (IRSS) – Clinical Research Unit of Nanoro (CRUN), a Burkina Faso-based medical research center, to help us answer some questions that emerged when a team of GiveWell researchers dug into the monitoring and evaluation data we received on SMC campaigns led by Malaria Consortium.

At the end of each annual SMC round, external firms, selected by Malaria Consortium through an open bidding process, conduct household interviews to estimate the number of children who received preventive malaria medication during the campaign.⁴This is in addition to monthly household surveys conducted by Malaria Consortium following each monthly cycle that are used for their monitoring and evaluation purposes. We believe the surveys provide relatively strong evidence that a high proportion of the targeted population is reached, but the surveys aren’t perfect. We’re particularly uncertain about two potential sources of bias:

• First, we know from past experience that there are many ways bias can creep into monitoring and evaluation processes. We don’t know whether this is the case for Malaria Consortium’s SMC program, but having an independent organization gather additional data will provide us with more information about potential biases.
• Second, the surveys depend on caregivers accurately reporting whether their children received all of the doses of SMC medication. During an SMC campaign, a community distributor provides each child with the first day’s medication, then gives the remaining doses to the child’s caregiver, who then administers one dose on each of the following two days. Our current understanding is that receiving all doses is critical for full protection of children from clinical malaria, and we want to have a clear picture of the extent to which this takes place. We think there is a risk caregivers are not giving medications on day two and three but reporting they are, either because they misremember or because they feel pressure to report that they followed the recommended treatment correctly.

The work, implemented by CRUN with IDinsight providing validation governance, project management, technical backstopping, and quality assurance support, will address both of these potential sources of bias. To address the question of bias during data collection, CRUN will conduct an independent coverage survey, using an approach similar to that used by Malaria Consortium, in around 1,500 households across the six regions of Burkina Faso where GiveWell funds Malaria Consortium’s SMC program. The survey will happen around the same time as Malaria Consortium’s end-of-round survey. This will provide us with independent coverage data that we can compare to the results from Malaria Consortium.

The study is designed to provide us with more information about the extent to which children receive all of the doses of SMC medication. CRUN will collect dried blood samples from all eligible children enrolled in the study sample, which will provide us with two types of important information.⁵All biological sample collection will be conducted under the applicable ethical approvals, informed consent procedures, and participant protection requirements in Burkina Faso.

• First, the SMC drug levels found in children’s blood will be compared to the self-reported adherence estimates collected both in Malaria Consortium’s survey and the independent survey. We think this will allow us to check the reliability of self-reported adherence estimates. If this proves to be a feasible approach, it could be implemented across GiveWell’s broader SMC portfolio as a way to triangulate and confirm other sources of data.
• Second, the blood samples will also be tested for malaria parasites; by assessing both the drug concentration and malaria parasites from the same children, we will learn how receiving each dose of medicine affects malaria parasite levels. We’ll also be able to combine what we learn with the results of a randomized controlled trial that we’ve recently funded that looks specifically at how malaria parasite levels correlate to malaria morbidity. This will tell us how SMC’s effectiveness changes with the number of doses received.

What we learn will help us refine our cost-effectiveness estimates, which will help us make better decisions in the future. For example, if we learn children are receiving fewer doses than we currently estimate, and the second and third doses are important to SMC’s effectiveness, we would revise downward our estimate of the program’s benefits. What we learn could also provide useful insights for increasing the impact of Malaria Consortium’s program. For example, if we find adherence is lower than we expect, we could consider changes in delivery, such as having a community distributor observe the children being given all doses of the medication or providing more information to caregivers about the importance of giving children all of the doses.

These are just a few of the malaria grants we’ve made recently to get the information we need to make even better funding decisions in the future—and we’re funding an increased number of these value of information grants across our grantmaking areas.

Identifying Ways to Increase Coverage of Our Core Programs

With a larger, more specialized research team, we have also been looking for ways to increase the number of people that benefit from SMC and nets.

For example, we estimate that only about 63% of insecticide-treated nets provided through GiveWell-funded mass distributions are hung above sleeping spaces to provide protection against mosquitos.⁶See this section of our report on insecticide-treated nets. Because so many nets are distributed—more than 180 million globally in 2024⁷“In 2024, a total of 181 million ITNs were distributed globally by NMPs [national malaria programs] in malaria endemic countries.” World Health Organization, World Malaria Report 2025, p. 68. (GiveWell provided funding in 2024 for around 28 million⁸Around 24.5 million via AMF, and 3.6 million via Malaria Consortium. Note that GiveWell funding approved in 2024 may have been for net campaigns during future years.)—increasing usage by even a small amount could make a big difference. We recently made two grants to inform our longer-term aim of increasing the number of people using the nets they’ve received.

The first grant, to Malaria Consortium and the Behavioural Insights Team (BIT), seeks to understand the most significant barriers to net use. In the initial phases of the project, researchers worked to identify some of the barriers that prevent people from regularly using mosquito nets by reviewing the scholarly literature, talking with people in Nigeria and Uganda, and directly observing people hanging, using, and maintaining nets. The researchers used behavioral science methodologies to identify a number of barriers to net use—such as misconceptions about the nets, low risk perception, or practical obstacles—then came up with possible interventions to address them. After ranking them by feasibility and impact, researchers identified the top two: (1) reinforcing positive social norms around net use and (2) distributing preferred types of nets. Malaria Consortium and BIT then conducted small pilots to determine the feasibility and acceptability of those interventions.

For example, they tested a range of net types and found some evidence that soft, colored (rather than white) nets were preferred in some of the communities in Nigeria and Uganda where they conducted their research. Those findings are based on a small, non-randomized sample; we don’t know whether that evidence is generalizable beyond those contexts, and we don’t know whether satisfying that preference would lead to an increase in net use. We are currently considering whether to fund a larger study on net preferences to learn more about whether the preliminary findings from the small pilot are consistent in other settings and to determine if this could be a cost-effective opportunity to increase net use.

The second grant we funded was to Tropical Health to carry out a small scoping study to begin to identify messages and ways of communicating that are likely to have a positive and measurable impact on net use in Nigeria. The findings of this initial scoping study have the potential to inform a grant for a larger evaluation of social and behavioral change interventions to increase net use, which would take place in Nigerian states where we have recently funded upcoming net campaigns, but which had not had net campaigns for at least eight years previously. Because of the different context, this study may have different findings and be an important complement to Malaria Consortium and BIT’s research.

Removing barriers to net usage is only one way to increase the number of people benefiting from malaria prevention programs. For example, most SMC campaigns take place in West Africa where strong evidence gives us confidence in the effectiveness of the drug combination used, but there are millions of children in eastern and southern Africa that could potentially benefit from chemoprevention.

We have substantial uncertainties about the effectiveness of SMC drugs in eastern and southern Africa, where malaria parasites are resistant to one of the drugs. While we have funded trials and supported some SMC programs in that region, before we scale up our funding we would like stronger evidence on which drug combinations work and whether using certain drugs could increase resistance.

To address our uncertainties and learn more about whether chemoprevention campaigns could be fruitfully expanded to help more children, we recently funded the largest individualized randomized controlled trial of SMC outside of West Africa. The trial, which we discussed in a recent podcast episode, will test three drugs alone and in different combinations across roughly 7,000 children in Malawi. We’ll learn about the efficacy of the two drugs currently used in SMC (sulfadoxine-pyrimethamine and amodiaquine), as well as an additional drug (chloroquine) that had previously shown resistance but might now be effective again.

Depending on what we learn, this trial could lead to cost-effective opportunities to provide preventive malaria medication to millions of additional children each year.

Expanding Our Portfolio Beyond Our Core Programs

Despite widespread implementation of very effective malaria prevention programs like SMC and nets, many people are infected and die each year. We think building a broader portfolio of cost-effective and evidence-informed strategies to prevent malaria is an important next step.

To determine which approaches to implement, National Malaria Control Programs (part of the Ministry of Health in countries where malaria is endemic) depend on guidelines from the World Health Organization (WHO), which systematically evaluates the safety and efficacy of potential treatments and flags relevant contextual factors for treatment selection. We believe that existing guidelines may not cover all optimal treatments, so we recently made a grant to WHO’s Global Malaria Programme to fund evidence reviews and convene a Guidelines Development Group (GDG) to update the guidelines with recommendations for two potentially promising malaria interventions: (1) single low-dose primaquine to reduce transmissibility of malaria parasites, particularly in areas at risk of drug resistance, and (2) intermittent preventive treatment in pregnancy for HIV-positive women. While sulfadoxine-pyrimethamine used as intermittent preventive treatment in pregnancy (IPTp) is the standard drug for malaria prevention in pregnancy, HIV-positive women cannot take it due to risk of adverse drug reactions following interactions with other medications. Recent evidence suggests alternative treatments, such as dihydroartemisinin-piperaquine, may be both safe and effective for this population.

The GDG meetings have formulated the relevant recommendations, currently being finalized by WHO and expected for publication in June 2026. Without our funding, we think that WHO wouldn’t have the capacity to review the evidence for these programs for several years.

GiveWell’s malaria team also recently launched a request for information, similar to recent RFIs from other GiveWell research teams. The team is looking for organizations that are able to cost-effectively implement interventions that are not currently widely implemented, such as perennial malaria chemoprevention (PMC) or technical assistance to increase routine delivery of nets. Based on the prior success of our water RFI, whose more than 200 applications led to 18 grants, we are optimistic that this approach will lead to promising opportunities that we may not otherwise have found.

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For more than a decade, GiveWell has been at the forefront of malaria prevention. As our team grows, we’re now able to move from funding existing programs to finding answers to important questions about the evidence, increasing coverage of life-saving programs, and supporting research on potential new ways to help people. We’ve taken on the challenge of reducing deaths from malaria in a way that would not have been possible even a few years ago, and we’re excited to continue expanding this work.