Research Roundup: Promising ETEC vaccine, Inhalable TB treatment, New helminth combination treatment

A two-year citywide experiment in Singapore found that releasing Wolbachia-infected mosquitoes was effective at reducing mosquito numbers and dengue transmission in the densely populated city, supporting their use as a complement to existing vector control methods and vaccines to control transmission of dengue and other mosquito-borne diseases. Wolbachia is a common type of bacteria found in insects that cannot make people or animals sick but can stop the dengue virus from replicating inside the Aedes aegypti mosquitoes that spread dengue and other viruses, reducing mosquito populations and disease transmission. The researchers divided the city into clusters, releasing sterile infected male mosquitoes in some areas while leaving other areas untouched. They found that where the infected mosquitoes were released, mosquito numbers fell sharply, and people living there were about 70 percent less likely to develop symptomatic dengue after a few months of exposure. A Phase 4 randomized controlled trial has provided further evidence of the safety and efficacy of shortened regimens of preventive tuberculosis (TB), which could help improve uptake and completion rates. The trial, conducted in Brazil, tested one- and three-month regimens of isoniazid and rifapentine, much shorter than the current standard regimen of isoniazid, which lasts six to nine months and has seen poor uptake and completion rates. Additional studies are needed to ensure safety and acceptability across diverse populations. A Stanford University research team has developed an affordable, battery/solar-operated microscope called Octopi that uses artificial intelligence (AI) to automatically diagnose malaria in blood samples in minutes, which could greatly improve access to early and accurate diagnosis in low-resource settings. Confirmatory malaria diagnosis is currently done through a long, technical process carried out manually by lab technicians. The team also developed a complementary tool to automate and standardize the process of preparing blood samples, which is open source, requires no electricity, and is cheap. 

A new study has found that five human cases of a mysterious, bat-borne virus in Bangladesh, initially thought to be Nipah virus, were actually caused by another emerging bat-borne virus called Pteropine orthoreovirus (PRV). Between late 2022 and early 2023, five patients were admitted to hospitals with severe symptoms, all of whom had consumed raw date palm sap, which is also consumed by bats. Health care workers thought they had the Nipah virus, for which bats are a known vector, but they all tested negative. Several of the patients continued to experience severe symptoms after being discharged, and one ultimately died the following year. Human PRV cases have been reported other countries, but typically resulted in much milder respiratory illness, suggesting that the virus may have undergone genetic changes, making it more transmissible and virulent. These findings underscore the need for robust, vigilant surveillance of emerging diseases, particularly bat-borne pathogens. Last week, the Population Council announced that it has executed a global, exclusive license agreement for the Nestorone®/Testosterone (NES/T) male contraceptive gel, transferring the program to Contraline Inc., which will lead late-stage development toward potential global regulatory approvals as the first reversible contraceptive drug for men. The product, if approved, could transform contraception, enabling men to take on a responsibility that has historically fallen on women. NES/T is the most advanced investigational male contraceptive in the pipeline, and the Phase 3 clinical trial being planned is expected to be the first-ever Phase 3 trial of a hormonal male contraceptive. It is a daily topical gel that suppresses sperm production while maintaining normal testosterone levels, which was co-developed by the Population Council and the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health.  An early-stage trial evaluating a nasal spray vaccine for H5N1 bird flu found that the vaccine generated a strong immune response in rodents, a significant first step toward a vaccine capable of slowing the spread of bird flu, which in recent years has continued its worrying global spread among animal populations, with occasional human cases. While traditional injected flu vaccines are highly effective at preventing serious illness, they are less effective at reducing infection in the first place. Nasal vaccines, which work at the place of infection, can more effectively stop infections and prevent onward transmission to others. They are also believed be more effective against rapidly mutating viruses because they train the immune system differently than traditional vaccines, stimulating mucosal immunity in the nose and upper airway, and can respond to features of the virus that are shared across different strains, meaning they can remain effective for longer without needing updating. There are H5N1 vaccines stockpiled in several countries, but most of these were developed to target previously circulating strains of the virus and are poorly matched to the newer, rapidly mutating strains we have seen in recent years.