Malaria decoded: Jane Carlton on parasite biology, genomes, vaccines, and elimination hopes

Jane Carlton, director of Johns Hopkins Malaria Research Institute, explains how the malaria parasite operates, its multiple human species, and why genome sequencing has revolutionized drug and vaccine development. The discussion covers the Plasmodium falciparum and Plasmodium vivax life cycles, dormant liver stages, and the parasite’s ability to evade immunity. Carlton reviews the status of malaria vaccines, including Mosquirix (RTSS) and the newer R21, and the challenges posed by antigenic variation and drug resistance. The interview also explores global strategies for elimination, not eradication, and the multi-pronged efforts in vaccine rollout and vector control, with Zambia as a focal example. The talk ends with a look ahead at research directions and the Johns Hopkins Malaria Institute’s role in shaping a malaria-free future.

Introduction and guest background

The episode features Chris Smith in conversation with Jane Carlton, director of the Malaria Research Institute at Johns Hopkins University. Carlton outlines a career spanning Edinburgh, Florida, NIH, and NYU, culminating in leadership of a major malaria research program. She highlights how her early genetics work and genome sequencing efforts on malaria parasites redefined the field, paving the way for new drug targets and vaccine strategies. The discussion emphasizes malaria’s global impact, noting hundreds of millions of cases and hundreds of thousands of deaths each year, with the burden most severe among young children in sub-Saharan Africa. Carlton also reflects on the collaborative nature of large-scale genome projects and the role of team science in malaria discovery.

"Parasites are fascinating organisms. They live in or on a host and usually to the detriment of that host." - Jane Carlton, Director of the Malaria Research Institute at Johns Hopkins University

Malaria life cycle and disease mechanism

Carlton provides a concise account of how malaria is transmitted by female Anopheles mosquitoes, which inject parasites during blood meals. The parasites first reach the liver, where they multiply, then burst into the bloodstream, causing the clinical symptoms that define malaria such as fever, muscle aches, headaches, and chills. The blood stage also includes sexual stages that, when taken up by a biting mosquito, propagate the cycle. Carlton emphasizes the parasite’s capacity to inhabit multiple cell types across both human and insect hosts, and the complexity of studying its numerous developmental stages. The discussion stresses that symptoms may not appear until weeks after exposure, making travel history a critical clue for clinicians in non-endemic areas.

"The malaria parasite life cycle is incredibly intricate, and all of those different stages we have to study." - Jane Carlton, Director of the Malaria Research Institute at Johns Hopkins University

Genomics, drug targets, and vaccine landscape

The conversation shifts to genomics, with Carlton recounting her leadership in decoding the genomes of several malaria parasites, including Plasmodium vivax and rodent models, and participating in the broader effort to sequence Plasmodium falciparum. She explains how genome data enable population studies, reveal drug-resistance markers, and identify parasite proteins that differ from the human host, thus offering potential drug or vaccine targets. Carlton notes the existence of about six human malaria species, and she highlights the dormant liver stage of vivax that can relapse years after an initial infection. The section also covers vaccines in use or under development, including the World Health Organization approved vaccines RTSS (Mosquirix) and R21, with recent deployment in several countries and ongoing evaluation of effectiveness in large-scale programs such as Zambia.

"Yes, we are really at the beginning actually. It's been incredibly difficult to generate a good vaccine for malaria." - Jane Carlton, Director of the Malaria Research Institute at Johns Hopkins University

Directorship, projects, and elimination goals

Carlton describes taking on the Johns Hopkins Malaria Research Institute directorship about three years prior, building on a foundation funded by Michael Bloomberg and a broad international network. The institute conducts roughly 16 major projects across Africa, including Zambia, Uganda, Kenya, Tanzania, and Ethiopia, focusing on vector control, vaccine implementation, and surveillance for drug resistance. She explains vaccine rollout logistics, such as the four-shot schedule for the R21 vaccine, and discusses efforts to deploy vaccines through field sites and to monitor immune responses. The discussion expands to broader strategies that could push toward malaria elimination, including vector-targeted interventions, the potential for genetic modification of mosquitoes to block parasite development, and more effective bed nets and repellents. Carlton underscores the need for a coordinated global effort and continued funding to sustain progress toward elimination rather than complete global eradication.

"Eradication is completely getting rid of that particular disease globally. And elimination on the other hand, is when certain countries have managed to rid the disease." - Jane Carlton, Director of the Malaria Research Institute at Johns Hopkins University

Closing notes and the path forward

The interview closes with a forward-looking view on malaria research and outreach. Carlton reflects on the role of vaccines, novel technologies such as mRNA approaches for vaccine development, and the importance of field studies in vaccine effectiveness. The conversation gestures toward a future in which integrated strategies—vaccination, vector control, and health-system strengthening—could materially reduce transmission and move many countries toward malaria-free status. The episode also signals ongoing collaboration with the Naked Scientists to deliver the Malaria Minute, a concise update on malaria science and its real-world impacts. The host invites listeners to engage with the program and follow updates via the show’s channels.

"I’m hopeful, I’m always hopeful, that we’ll be able to eliminate malaria, if not eradicate it in many of those endemic countries." - Jane Carlton, Director of the Malaria Research Institute at Johns Hopkins University