Breakthroughs Blog: Vaccines

Interested in more global health innovation news? Every week GHTC scours media reports worldwide to deliver essential global health R&D news and content to your inbox. Sign up now to receive our weekly R&D News Roundup email. A new study published in The Lancet Infectious Diseases ahead of World Malaria Day last week found that adding a low dose of the widely available antimalarial drug primaquine to artemisinin-based combination therapy is safe and effective at blocking Plasmodium falciparum malaria transmission in young children in areas of low- and moderate-to-high transmission. The new study fills a gap in knowledge of the safety and efficacy of this approach for young children, who face the highest burden of clinical malaria and are particularly at risk of artemisinin-resistant strains but could face adverse complications from adult formulations of primaquine. The findings highlight the need for child-friendly formulations of primaquine and support the expanded use of the drug in regions with a moderate-to-high transmission rate and the threat of artemisinin partial resistance.The Drugs for Neglected Diseases initiative, the National Health Service University Hospitals of Liverpool Group, and the University of Liverpool have initiated a clinical trial in Liverpool, United Kingdom to test an oral drug for visceral leishmaniasis, one of the world’s deadliest parasitic diseases. Current treatments for visceral leishmaniasis, which is almost always fatal if left untreated, include daily injections for up to 17 days, which can cause immediate pain, as well as nausea, vomiting, and more serious complications. The new oral drug, DNDI-6899, is easier to store, transport, and administer than current treatments. If proven successful, the drug could help make treatment more accessible to those who need it most.DioSynVax and ACM BioLabs have signed a new deal to jointly develop a next-generation avian flu vaccine with the potential for mucosal vaccine delivery, as the virus continues its worrying spread. The mRNA vaccine targets all major clades of the H5 avian flu subtype and could be scaled for rapid distribution globally in the case of a pandemic. The vaccine is also designed to be delivered via nasal spray, which could help increase uptake; to induce mucosal immunity, which helps fight the pathogen before it starts circulating the body; and to be temperature stable, enabling rollout in lower-resource settings.

In 2001, I traveled to Ghana as a graduate student working on a US Agency for International Development-funded decentralization program. I arrived armed with materials on local governance best practices. But the mayors I met were focused on urgent public health issues: clean water, HIV/AIDS, tuberculosis, and malaria. That trip, meant to be an early lesson in governance, became my first and most personal education in global health. It also nearly killed me. I was taking mefloquine weekly to prevent malaria. Toward the end of our stay, my partner and I set off to explore the country. Somewhere along the way, I developed what I believed to be giardia. That infection likely compromised the absorption of the mefloquine and left me dangerously vulnerable. One night in the village of Kokrobite, I woke with a high fever and chills so intense I could barely stand. A local man saw me and immediately recognized it as malaria. He arranged for a taxi to take me back to Accra. Before I left, he handed me a small, crumpled packet labeled in Chinese characters. Inside was a blister pack of pills. The only word written in English on the package was artesunate. He told me it would help, and, in that moment, sick, scared, and weak, I took it. At the hospital, a blood smear confirmed that I had cerebral malaria caused by Plasmodium falciparum, the deadliest strain. Cerebral malaria can cause brain swelling, coma, and death. I drifted in and out of consciousness for days. At one point, hospital staff told my partner that there was nothing more they could do. I should “go home” and be “as comfortable as possible.”My partner worked relentlessly to get me on one of the next flights back to the United States. I was so sick that the airline nearly refused to let me board. Once we arrived home, I was seen right away by an infectious disease doctor at Johns Hopkins Hospital. After reviewing my labs and the herbal remedy package, he said plainly: this saved your life. The artesunate had bought me enough time to survive the journey and begin treatment. At the time, the World Health Organization had not yet formally endorsed artemisinin-based combination therapies (ACTs) as the global standard for P. falciparum malaria. That came in 2006. But the effectiveness of artesunate alone was already well known in many parts of the world. That medicine saved my life.I missed several weeks of school but made a full recovery. Without that drug and the help of my partner (now my husband) and friends in Accra, I wouldn’t be here today. More than two decades have passed, and we've made tremendous progress. Insecticide-treated bed nets, rapid diagnostic tests, and ACTs have saved millions of lives. Two malaria vaccines, RTS,S and R21/Matrix-M, have been approved. Long-acting monoclonal antibodies are showing promise as seasonal protection for children. Newer insecticide-treated nets help counter resistance. And researchers are exploring RNA-based therapeutics and single-dose cures.Many of these breakthroughs are being developed by members of the Global Health Technologies Coalition, where I now serve as Executive Director. These tools represent our best chance not just to control malaria but to end it.But progress is not guaranteed. Cuts to foreign assistance and global health research and development are already slowing the progress of innovations in the pipeline. Some promising tools may be delayed or abandoned. That means more children at risk, more untreated infections, and more drug-resistant strains emerging. The parasite has evolved before. It will do so again if we let it. And malaria is no longer a disease that happens mostly outside of the United States. In the past two years, locally acquired cases have been reported in Florida, Texas, and Maryland. Climate change, global travel, and changing mosquito habitats are making malaria a threat we can no longer treat as distant. I know how thin the line is between surviving this disease and not. For me, it’s not abstract. It’s the memory of a fevered body, the generosity of strangers, and a medicine in the right place at the right time. This World Malaria Day, I urge leaders and policymakers to stay the course. The science is moving forward. But science alone isn’t enough. If we don’t finish what we’ve started, we risk letting malaria surge back and take more lives with it. Science has given us the tools. The question now is whether we will act in time or let the disease outpace us once again. 

Interested in more global health innovation news? Every week GHTC scours media reports worldwide to deliver essential global health R&D news and content to your inbox. Sign up now to receive our weekly R&D News Roundup email. The Sabin Vaccine Institute has launched a multi-site Phase 2 clinical trial, supported by the Biomedical Advanced Research and Development Authority, in the United States to test its Marburg vaccine candidate, as outbreaks of the virus, for which there is no approved vaccine, grow in frequency. This trial builds on previous Phase 2 testing in Kenya and Uganda, as well as an open-label Phase 2 trial in Rwanda during the country’s outbreak last year. These trials in the African regions where Marburg and other similar viruses are most common or endemic are key to ensuring the vaccine is effective in the populations currently facing the highest risk of outbreaks. In addition, this new trial in the United States provides key safety and immune response data in non-endemic populations, helping prepare us for the possibility of outbreaks outside of the virus's typical range.Researchers have discovered a small antibody fragment that can block fertilization by targeting a key protein on the egg's surface, potentially paving the way for a nonhormonal contraceptive method. The fragment was found to be effective in mice, and it could potentially have fewer side effects due to its small size. Currently available hormonal contraceptive methods can cause side effects, like mood changes, headaches, or increased risk of blood clots, leading researchers to look for nonhormonal options for people who do not want to or cannot use hormonal methods. The researchers will next develop a similar antibody for human targets and test it in IVF experiments.The Drugs for Neglected Diseases initiative (DNDi) and partners initiated Phase 2 clinical trials in Malawi and Tanzania testing a new, easier-to-administer, and patient-friendly formulation of flucytosine, a medicine used to treat cryptococcal meningitis, which is a major health threat to people with weakened immune systems, including those with advanced HIV disease. Currently, flucytosine can be difficult to administer in resource-limited settings, and many countries face limited supply. As a result, access to timely treatment is limited in Africa, where the disease kills up to 70 percent of those who get it. The new formulation reduces dosing frequency from four times a day to just twice daily, is easier to take with water or through a nasogastric tube, and is suitable for outpatient self-administration.

Interested in more global health innovation news? Every week GHTC scours media reports worldwide to deliver essential global health R&D news and content to your inbox. Sign up now to receive our weekly R&D News Roundup email. A new study led by a multi-country research team has found that the Xpert MTB/Ultra molecular diagnostic test for stool samples, which is currently only recommended for tuberculosis (TB) diagnosis in children, could serve as an alternative TB diagnosis option for adults living with HIV—a potential gamechanger for improving diagnosis among this population. Thirteen percent of the 1.25 million TB deaths in 2012 were among people living with HIV, but access to the sputum- and urine-based tests currently recommended for TB diagnosis in this population is limited in many settings, and they are not effective for all people living with HIV. The researchers found that, compared to current tests, the stool test was effective, and, in some cases, even identified additional cases that were not detected in sputum or bacterial culture.The Combating Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator (CARB-X) last week announced a $3.7 million award to ArrePath to support its first-in-class antibiotic for treating complicated urinary tract infections caused by multidrug-resistant Enterobacterales bacteria. If it proves successful, the novel antibiotic class could target the vast majority of multidrug-resistant Enterobacterales infections. The class of antibiotics also has attributes that suggest it could be administered orally or intravenously, allowing more flexibility for patients. ArrePath identified the new class using an artificial intelligence and machine-learning-enabled approach.Last week, the US Food and Drug Administration approved a freeze-dried formulation of Bavarian Nordic’s vaccine for mpox and smallpox, Jynneos, enabling additional flexibility in stockpiling doses of the vaccine to prepare for future outbreaks of smallpox or mpox. The freeze-dried vaccines are easier to store and transport and have a longer shelf life than the frozen liquid version, which was approved in 2019. Bavarian Nordic will deliver the first freeze-dried vaccines later this year.