Breakthroughs Blog: Vaccines

A Phase 1 randomized controlled trial found that a single dose of the ChAdox1 Rift Valley fever (RVF) vaccine was safe, tolerable, and elicited a strong immune response in 30 adults in Uganda, where RVF—a neglected, mosquito-borne disease that is considered a significant public health threat and a priority for vaccine development—is endemic. The trial was led by researchers at the Uganda Research Institute and the London School of Hygiene and Tropical Medicine Research Unit in Uganda and provides the first evidence supporting the vaccine from a trial in an endemic setting. While the vaccine could potentially be transformative for RVF prevention, further research is needed that follows participants for a longer period and includes a larger group of participants, including children, pregnant women, and immunocompromised people. Last week at the American Society of Tropical Medicine and Hygiene annual meeting, Medicines for Malaria Venture and Novartis shared the results of a Phase 3 study testing a new malaria treatment, known as GanLum, finding that the treatment was highly effective at treating malaria, including drug-resistant cases, and could also block disease transmission. GanLum was found to be 99.2 percent effective in curing patients, more effective than standard artemisinin-based combination therapies, the gold-standard malaria treatment introduced more than 20 years ago, whose use has been undermined since the emergence of partial resistance. The developers say that, pending regulatory approval, the new treatment could be rolled out within the next few years. South African pharmaceutical company Biovac is launching trials of a cholera vaccine, which, if it proves successful, could become the first vaccine developed from start to finish on the African continent. Africa faces the brunt of the global cholera burden but is almost entirely reliant on vaccines made internationally, which has become increasingly challenging in recent years as cases have risen sharply around the world and vaccine stocks have diminished. The African Union has committed to increasing the proportion of routine vaccines used in Africa that are manufactured on the continent from just 1 percent now to 60 percent over the next 15 years, an effort triggered by the access challenges African countries faced during the COVID-19 pandemic. 

The World Health Organization's (WHO's) TB Vaccine Accelerator Council recently published a new report calling for action to ensure equitable access to future tuberculosis (TB) vaccines currently in the pipeline. While the only licensed vaccine for TB is 100 years old and has limited effectiveness in adolescents and adults, as of September, there are 16 candidate vaccines in clinical development, six of which are in Phase 3 trials. WHO estimates that a vaccine for adolescents and adults that is at least 50 percent effective could avert up to 76 million TB cases and 8.5 million deaths over 25 years. However, as the report claims, global demand could far exceed supply in the initial years after a vaccine is approved because there is no designated funding for such a rollout in low- and middle-income countries most affected by TB, which are already facing significant funding shortfalls. In anticipation of these potential bottlenecks and barriers to access, the report identifies six solutions to encourage countries with a high burden of TB, manufacturers, and other funders and stakeholders to start preparing now for the rollout to ensure future vaccines can reach people who need them faster. In a Phase 1 randomized controlled trial, an experimental intranasal vaccine against multiple H5N1 avian flu strains generated a broad immune response, demonstrating the potential of such a vaccine to play a major role in preparing for outbreaks of emerging viruses with evolving strains, as H5N1 continues its worrying spread. The University of Maryland research team tested the vaccine against a placebo in 40 adults between 18 and 45, finding that the vaccine was safe, well-tolerated, and stimulated immunity at various doses. One group received a vaccine dose combined with an adjuvant, an ingredient used to trigger a stronger immune response, and their immune systems were better able to neutralize infected cells for longer, suggesting that the use of an adjuvant could be a promising approach that might allow for lower doses, which could stretch limited vaccine supplies in the event of an outbreak. Last week, IAVI published new findings from the first-in-human Phase 1 clinical trial of its Lassa virus vaccine candidate, which show that one dose of the vaccine triggers robust and long-lasting immunity and is safe. There are no vaccines or treatments currently licensed against the dangerous illness, which causes thousands of deaths in endemic West Africa and has been designated as a priority pathogen with pandemic potential. The trial enrolled 114 volunteers in Liberia and the United States. The candidate, now undergoing a Phase 2a trial in West Africa, is currently the most advanced Lassa fever vaccine candidate in the pipeline and uses the same platform as Merck’s single-dose Ebolavirus vaccine, which is approved in more than a dozen countries. 

A systematic review and meta-analysis of studies looking at the effectiveness of typhoid conjugate vaccines found that they are highly effective in preventing typhoid fever in countries where the infection is endemic, adding to the collection of real-world evidence supporting their use. Despite the high burden of typhoid fever—an infection caused by Salmonella enterica serovar Typhi—in Africa and Asia, only ten countries to date have added the vaccines to their national immunization programs. There are three vaccines for preventing typhoid fever that are currently recommended and licensed by the World Health Organization. Last week, California-based True Diagnostics announced that it had received an award of upward of $11 million from the Biomedical Advanced Research and Development Authority (BARDA) to support the development of a blood-based rapid antigen test for Ebola and Marburg viruses. The test, if it proves effective, could help boost testing capacity and national preparedness for outbreaks of pathogens with pandemic potential like Ebola and Marburg viruses, which have caused worrying outbreaks in Africa in recent years. Specifically, the funding will support the further development, validation testing, and regulatory submissions of its VeriClear EbV MARV Rapid Antigen Test to detect and differentiate Ebola and Marburg viruses in fingerstick blood samples.   A research team presented new data at the 2025 European Society for Medical Oncology Congress in Berlin, Germany last week, showing that cancer patients who received COVID-19 mRNA vaccines within 100 days of starting immunotherapy drugs survived more often than non-vaccinated patients. These findings suggest that mRNA vaccines could help improve outcomes for cancer patients being treated with immunotherapies and even patients with treatment-resistant cancers. While these results are preliminary and need to be confirmed in an upcoming Phase 3 randomized clinical trial, scientists say they could revolutionize cancer care, perhaps even paving the way for a universal, off-the-shelf vaccine for cancer. 

Last week, Monod Bio announced that it has received a $750,000 grant from the Gates Foundation’s Grand Challenges initiative to develop a point-of-care test for preeclampsia, a pregnancy complication characterized by high blood pressure, which is a leading cause of maternal deaths. Preeclampsia is a particular challenge in low- and middle-income countries where complex and high-cost testing is not always accessible. The test is designed to detect two protein biomarkers associated with preeclampsia and utilizes an artificial intelligence-derived algorithm to analyze the results. The developers aim for the test to be a rapid, one-step tool that delivers results in under 15 minutes, without requiring complex and expensive laboratory infrastructure and highly skilled health care workers. The Coalition for Epidemic Preparedness Innovations is partnering with the Serum Institute of India, the largest vaccine manufacturer in the world, to develop a new vaccine targeting H5N1 avian flu that elicits a broad immune response across multiple H5 viral strains. The vaccine candidate is intended to serve as a prototype vaccine for Disease X, a yet-to-arise pathogen with pandemic potential. This project is part of CEPI’s 100 Days Mission aimed at having a vaccine within 100 days of identifying a new pandemic threat.A research team from the German University of Würzburg has developed a method for diagnosing viral infections that leverages the unique features of the human tongue, which could be incorporated into gum or a lollipop. The researchers were inspired by prior work on dental implants, developing a method that uses chemical sensors to trigger a taste change in individuals infected with the flu, even before they experience symptoms. The researchers are now working to figure out how to make their method more sensitive and low-cost, tailor it to other diseases, test it on people with different levels of taste perception, and pair it with an app that would enable people to self-report infection, which could help generate real-time data across populations in the case of a large-scale influenza outbreak.