Research Roundup: Barriers to TB immunization, malaria's genetic diversity, and IPM's dapivirine ring
In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week.
For many years, ineffective treatment plans and archaic diagnostic tools have stood as a barrier to tackling tuberculosis (TB). More recently, new drugs and diagnostics have emerged. Yet, availability has not always translated to widespread access. For example, despite the availability of new rapid diagnostic tools like GeneXpert, it is estimated that over 40 percent of new TB cases go undiagnosed or are not reported and use of older, less accurate sputum tests still outpace use of the GeneXpert. Though new drugs like bedaquiline and delamanid are not available, more than 75 of patients who need them do not have adequate access. A number of hurdles to adoption and scale-up exist from lack of funding for TB programs to high costs to implementation failures Action is needed by global leaders and innovators to break down these barriers if the global community wants to achieve its goal of eradicating TB by 2030.
Malaria is more complex than scientists previously thought. In a recent study published in the Proceedings of the National Academy of Sciences, scientists used DNA fingerprinting to track malaria on a cellular level. They found that the parasite has a heightened level of genetic recombination developed during meiosis, leading to a wide variety of malaria strains. This suggests that malaria can evade immune system response, acting as a chronic disease—and it means there is no one-cure-fits-all solution. Because of the incredible amount of genetic diversity malaria can have in the body, one vaccine solution may not work for all individuals, casting doubt on the efficay of vaccines now in development. While this discovery makes malaria harder to prevent and eradicate, scientists have also discovered that malaria isn’t as transmissible as it first seemed, with the parasite only causing five or six secondary cases from one original infection, whereas it was previously thought one case could subsequently infect dozens of individuals.
The International Partnership for Microbicides (IPM) has announced a clinical trial that is hopeful to significantly reduce cases of HIV in Sub-Saharan Africa and around the world. The clinical trial will use the IPM-developed dapivirine ring, a small silicone ring inserted in the vagina, releasing a contraceptive (levonorgestrel) and an anti-HIV drug (dapivirine). The ring is easy to insert and lasts three months. Building on the previous ring that only released dapivirine, having the ring also act as a contraceptive will not only reduce the likelihood of HIV infecting women, but will also provide women with the choice to protect against unwanted pregnancy. This trial is especially important because women are most at-risk for contracting HIV, especially in countries with low rates of condom use. IPM hopes to have the ring ready for shipment globally by 2020.