For decades, the fight against malaria has leaned on the same weapons: mosquito nets, insecticide sprays, and public awareness campaigns. Yet the disease continues to kill more than 600,000 people each year, according to the World Health Organization.
Rwanda had been one of the success stories. Between 2016 and 2023, malaria cases in the country fell dramatically—from nearly five million infections to just 430,000. That 90 per cent reduction, hailed by health experts, was the result of sustained national campaigns and community-level action.
But those hard-won gains are now at risk.
In 2024, the number of malaria cases jumped by more than 45 per cent in a single year, climbing to 620,000, according to the Rwanda Biomedical Centre (RBC). “We’re experiencing a surge in the disease,” said Aimable Mbituyumuremyi, division manager for malaria and other parasitic diseases at the RBC. “We’re considering using vaccines since all other measures have yet to work and malaria cases are increasing.”
Rwanda had opted out of the first round of malaria vaccine rollouts by WHO and Gavi in 2023, confident that its steady progress would hold. But the sudden rebound of infections has forced policymakers to reassess.
The setback mirrors a wider challenge across sub-Saharan Africa, where malaria remains a stubborn daily threat. Traditional methods have slowed but not stopped transmission. Now, the WHO is backing a new addition to the malaria-fighting toolkit—an unassuming device, simple in design but potentially transformative.
Earlier this month, SC Johnson, the household products company best known for brands like OFF! and Raid, announced a milestone: the WHO has issued a policy recommendation endorsing spatial repellents as a tool in the fight against mosquito-borne diseases, particularly malaria. At the same time, WHO granted prequalification status to SC Johnson’s Guardian and Mosquito Shield spatial repellents—marking the first time in 25 years that a new class of vector-control product has received such backing.
The devices, which resemble thin plastic cards, can be hung in semi-enclosed areas like homes and classrooms. Once deployed, they emit a slow, consistent dose of a repellent that deters mosquitoes from entering the space. Unlike insecticides, these repellents don’t kill the insects—they make the environment uninviting to them.
It’s an approach that’s already showing promise. Clinical trials conducted over the past decade in Indonesia, Peru, and Kenya found that spatial repellents could reduce disease transmission by as much as 33%, according to data submitted to WHO. Guardian, the larger of the two products, can provide up to one year of protection per unit.
“We’ve been using the same tools for a long time, and they’ve saved millions of lives,” said Richard Allan, CEO of The MENTOR Initiative, a nonprofit focused on vector-borne disease control. “But those tools aren’t reaching everyone—or working everywhere. People need options that fit their realities. These spatial repellents do that.”
SC Johnson began developing spatial repellent technology more than a decade ago. Since then, the company has invested over $100 million in research and development, working in collaboration with the Bill & Melinda Gates Foundation, Unitaid, and several public health organizations.
The goal wasn’t just innovation, but scalability. In July 2024, SC Johnson opened two high-speed manufacturing lines in Nairobi, capable of producing 20 million units annually. Another facility, in Pilar, Argentina, is set to double global output in 2025.
Once operating at full capacity, the company estimates it will be able to protect 20 million people each year.
“Getting WHO’s recommendation was a major step, but it’s only the beginning,” said Alan VanderMolen, Chief Communications Officer at SC Johnson. “Now it’s about getting these tools into the hands of people who need them most.”
Since 2013, SC Johnson says its public health division has reached over 110 million people with mosquito control products and programs. But with the new WHO endorsement, officials hope the spatial repellent approach can be integrated into national malaria strategies across endemic regions.
Experts have cautioned that spatial repellents aren’t a magic bullet—and they’re not meant to be. Rather, they are an additional layer of defense in areas where bed nets and sprays fall short, especially where homes lack enclosed sleeping quarters or where people are active during peak mosquito hours.
“These tools are about meeting people where they are,” said Allan. “If you’re a schoolchild doing your homework in the evening or a shopkeeper working after dark, a bed net doesn’t help you much. But a spatial repellent might.”
As the climate warms and mosquito habitats expand, the urgency for flexible, scalable solutions is growing. SC Johnson’s new products, backed by science and now policy, offer one of the first real additions to the global anti-malaria toolkit in a generation.
Experts say, if successful, they may not only prevent hundreds of thousands of infections—but change the way public health thinks about disease prevention altogether.
