Malaria at a Crossroads: Johns Hopkins Experts Warn of Rising Threats Despite Vaccine Progress

Malaria remains one of the most persistent and complex infectious diseases globally, and despite recent progress, experts warn that the fight is entering a more fragile phase. In a Johns Hopkins briefing held this morning, researchers outlined both encouraging advances and serious emerging threats that infection prevention professionals should be watching closely.

Jane M. Carlton, PhD, is director of the Johns Hopkins Malaria Research Institute at the Johns Hopkins Bloomberg School of Public Health and a Bloomberg Distinguished Professor in the Department of Molecular Microbiology and Immunology at the School and in the Department of Biomedical Engineering at the Johns Hopkins Whiting School of Engineering., emphasized the scale of the ongoing burden.

“Malaria is one of the big 3 global infectious diseases… one of the deadliest and most burdensome in human history,” Carlton said.

According to the latest estimates, there were approximately 280 million cases and 600,000 deaths worldwide, with the vast majority occurring in children under 5 years of age. For infection preventionists (IPs), this underscores a familiar reality: High-burden infectious diseases continue to disproportionately affect vulnerable populations.

A Complex, Evolving Threat

Malaria is not a static disease. It is driven by a mosquito-borne parasite, with multiple species involved and a wide geographic footprint spanning more than 80 countries.

Carlton highlighted several converging threats that are complicating control efforts.

“The parasite has become resistant to artemisinin, which is the frontline antimalarial drug,” she explained, noting that resistance is now spreading in parts of Africa.

At the same time, mosquito resistance to insecticides is increasing, and even diagnostic tools are being challenged by evolving parasite strains.

“Diagnostic tests for malaria are failing due to the spread of mutant malaria parasite strains that cannot be detected,” Carlton said.

For infection prevention professionals, these dynamics mirror broader concerns about antimicrobial resistance and diagnostic limitations for other pathogens. The lesson is clear: Surveillance and adaptability are critical.

Vaccines: Progress, but Not a Solution Alone

After decades of research, malaria vaccines are finally being deployed. William Moss, MD, is a professor in the departments of Epidemiology and International Health at the Johns Hopkins Bloomberg School of Public Health; deputy director of the Johns Hopkins Malaria Research Institute; and executive director at the School’s International Vaccine Access Center, and he described this milestone as both significant and incomplete.

“A safe and effective malaria vaccine has been a holy grail for malaria control for many decades,” Moss said.

Two vaccines, RTS,S/AS01 and R21/Matrix-M, are now in use, and while their efficacy is lower than many other childhood vaccines, their impact is meaningful in high-burden settings.

“These vaccines are good and can prevent 10s of thousands of deaths each year, but there is a lot of room for improvement,” Moss said.

Importantly, he emphasized a key principle that resonates strongly with infection prevention practice.

“Vaccines don’t save lives. Vaccinations save lives,” Moss said, highlighting the importance of implementation and access.

For IPs, this reinforces the need to focus not only on tools but on uptake, adherence, and system-level execution.

A Layered Prevention Strategy

Vaccines are only one component of malaria control. Carlton outlined a range of additional interventions that are being deployed and developed.

These include dual-active-ingredient bed nets designed to overcome insecticide resistance, seasonal malaria chemoprevention for children, and novel approaches such as genetically engineered mosquitoes and improved repellents.

“There are several new tools… being rolled out,” Carlton said, emphasizing that progress depends on combining strategies rather than relying on a single intervention.

This layered approach is directly aligned with infection prevention principles across health care settings, where no single intervention is sufficient to control transmission.

Climate, Conflict, and Changing Risk

Beyond biological challenges, external factors are reshaping malaria transmission patterns.

Carlton pointed to humanitarian emergencies and climate change as key drivers. “In 2023, there were an estimated 80 million people displaced in malaria-endemic countries,” she said, noting that displacement disrupts health systems and increases exposure risk.

Climate change is also expanding the geographic range of malaria-carrying mosquitoes. “As temperatures rise, mosquitoes can move into previously malaria-free areas,” Carlton explained.

For IPs, these trends highlight the growing importance of environmental and population-level factors in infectious disease risk.

Surveillance and Real-Time Data

Advances in genomic surveillance and real-time tracking are helping researchers and policymakers respond more quickly to emerging threats.

Carlton said, “Decoding the genome or the genetic blueprint of the malaria parasite occurred more than 25 years ago, and it was a major milestone in the malaria research community. It led to the development of what are called genetic markers, or tags in the genome that can be used to track the spread of malaria parasites through countries and over borders, and this genomic surveillance, as we call it, is being used most recently to track the spread of new drug-resistant strains.”

She continued, “For example, while previous antimalarial drug resistance was found to spread from the Southeast Asian country into Africa, our current evidence collected by researchers using genomic epidemiology indicates resistance to fine antimalarial drug artemisinin has since independently within African countries. And so, researchers, for example, in Uganda, are working with policymakers on the ground to develop these real, dynamic epidural studies to discuss, then the implications of this type of drug resistance and the possible solutions.”

Moss added that new tools are improving visibility into vaccine rollout and disease burden. “We at the International Vaccine Access Center have a website called View-hub, where for many years, we've been tracking new vaccine introductions largely for routine childhood immunizations, and we recently implemented a malaria vaccine tracker,” she said. “People can go to that website, view hub.org, and look at those various modules. We also have information on disease burden, the dosing schedules, the type of vaccine that is being used in a particular country, RTSs or R 21, and follow new vaccine introductions going forward, and I hope we'll see more as I said earlier, particularly in those high-burden countries that have not yet used a malaria vaccine.”

These tools reflect a broader shift toward data-driven decision-making that infection prevention programs are increasingly adopting.

Funding: The Fragile Foundation

Despite scientific progress, both experts raised concerns about funding. Moss warned that disruptions in supply chains and program support could have immediate consequences.

“Even temporary disruption… can result in a high number of severe malaria cases, hospitalizations and deaths,” he said.

This is a critical takeaway for infection prevention professionals. Sustained investment is essential to maintaining gains, whether in malaria control or health care–associated infection prevention.

A Question of Access and Equity

During the briefing, Infection Control Today^® asked whether malaria vaccines would be available for travelers.

Moss clarified that current vaccines are not designed for that purpose.

“These vaccines really are designed for children living in endemic areas,” he said. “They require 4 doses, really, to see the protective immune response. It's a 3-dose primary series, followed by a booster dose 1 year later. There is work on developing for travelers. They're not yet available, but this has been a focus of research for many years, and, to protect our military, it is a major driver of malaria vaccine development. That's, in fact, the early motivation for the RTS, S vaccine development to protect military personnel deployed to malaria-endemic areas. In the coming years, we will see and perhaps even monoclonal antibodies that could be used to protect travelers. Of course, we do have drugs, chemoprophylaxis, that's highly effective in preventing malaria and travelers, as long as we take the doses.”

The Bottom Line for Infection Prevention

The Johns Hopkins briefing reinforces several themes that are highly relevant to infection prevention professionals.

Malaria control requires a layered approach, combining vaccines, environmental interventions, diagnostics, and surveillance.

Emerging threats such as resistance and climate change demand ongoing vigilance. And perhaps most importantly, progress depends on sustained funding, strong systems, and effective implementation.

As Moss summarized, “Malaria vaccines are just 1 tool in our toolbox… we can’t do it alone.”

For IPs, that message is familiar. The tools exist, but success depends on how well they are integrated, supported, and sustained.