Research Roundup: Rift Valley fever vaccine, Malaria treatment alternative, African-made cholera vaccine

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 team of chemists from the University of Warwick and Monash University has identified a promising, potent new antibiotic that seems to be much more effective than existing drugs against deadly superbugs like MRSA and shows no signs of resistance so far, encouraging news as the global threat of antimicrobial resistance continues to grow and the pipeline of new antibiotics continues to fall short. The molecule had been overlooked for decades as an intermediate chemical in the natural process to produce another known antibiotic, methylenomycin A, which was discovered 50 years ago, and despite having been synthesized multiple times, the synthetic intermediates have seemingly not been tested before for antimicrobial activity. The new antibiotic is much more potent than methylenomycin A itself—100 times more active against a range of serious bacteria. It could not only be a powerful new tool against rising drug resistance, but this work could also pave the way for new approaches to antibiotic discovery. A team of researchers has developed an antivenom using antibodies from a llama and an alpaca that can neutralize venom from some of the world’s most venomous snakes. Snakebites are a neglected public health issue that kill around 20,000 people in sub-Saharan Africa yearly. Current antivenom treatments are usually specific to a single snake species, and it can be difficult to identify which of the many types of venomous snakes is behind a bite, making timely, effective treatment difficult to achieve. The researchers exposed an alpaca and a llama to venoms from 18 of the most dangerous snake species in sub-Saharan Africa, isolated the antibodies that the animals produced against the venom, and then combined some of those antibodies in a single cocktail. In mice, the treatment protected against toxins from 17 African snake species and reduced skin damage. Many scientists previously thought that developing a broad-spectrum antivenom would require too many antibodies to be practical because some venom can contain up to 100 toxins, but this study shows that a combination of just a handful of antibodies can neutralize the venom of many snake species, paving the way for the development of similar broad-spectrum antivenoms for other areas where snakebites are a common public health challenge. Last week, Cepheid announced that its Xpert MTB/XDR test for tuberculosis (TB) drug resistance has been prequalified by the World Health Organization (WHO), enabling procurement through international agencies and greater access in areas with a high TB burden. The test is designed to detect resistance to multiple first- and second-line TB drugs from patient samples. It also delivers results quickly, within 90 minutes, allowing health care providers to make quicker, more reliable treatment decisions and have a better understanding of drug resistance, especially in regions with a high TB burden where timing and accuracy are critically important.