Research Roundup: A mosquito deliverer, the "fake" medicine crisis, and a promising typhoid vaccine

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. The release of antibiotics into the environment is a significant environmental threat, according to a new United Nations Environment Programme report. The presence of antibiotics have been found in soil deposits, lake and river sediment, and wastewater facilities around the world, suggesting industrial, human, and pharmaceutical disposal leads to traceable amounts of antibiotic compounds in the environment. This issue alarms experts because even minimal traces of antibiotics may lead to the continued evolution of antimicrobial resistant bacteria. While more research is needed on the consequences of antibiotics in the environment, experts suggest various strategies to help mitigate the problem including deploying improved methods to treat wastewater, treating animal waste before using it as fertilizer, and improving antimicrobial stewardship. An Army-developed Zika vaccine candidate (ZPIV) performed well across three Phase 1 clinical trials, according to new findings published in The Lancet. The three studies were designed to elicit information on background immunity, vaccine dosage, and vaccine schedule in adult populations. A total of 67 participants received two injections four weeks apart, and researchers found more than 90 percent of participants who received the ZPIV vaccine had an immune response to the virus. The Army developed the vaccine candidate in response to the 2015 outbreak, noting the need for a Zika vaccine not only to advance global health, but also to protect US service members and their families. Countries are restricting use of the world’s only dengue vaccine—Dengvaxia— following an announcement by developer Sanofi Pasteur raising safety concerns. The company discovered, from data analysis, that the vaccine could raise the risk of a deadly form of dengue for people who had not been exposed to the virus prior to vaccination. In response, the Philippines ceased an ongoing, mass immunization campaign, and Brazil tightened restrictions on the vaccine. While Sanofi stressed there were no reported deaths related to the dengue vaccine, they believe more severe cases of dengue may occur if an immunized individual, who was not previously infected before receiving the vaccine, is then subsequently infected with dengue. This rare complication leaves children at a higher risk of contracting the severe form of dengue, as they are less likely to have been exposed to infection before receiving the vaccine. Dengue sickens hundreds of millions of people and kills more than 20,000 every year, underscoring the need for a safe, effective, vaccine.

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. An individual’s immune response to the Zika virus—rather than the virus itself—may be the cause of severe nerve-related complications like Guillen-Barrè, according to a recent Yale University study. Researchers explored the spread of the Zika infection in mice who lacked a key antiviral response to the virus and found that immune cells known as CD8 T cells flood the brain during infection. While these T cells limit the virus from infecting nerve cells, they also attack the brain’s neurons, leading to complications like Guillen-Barrè, which may cause paralysis. These results suggest that suppressing immune response to the Zika virus may be a promising approach to preventing these complications. Developing new antiretroviral (ARV) drugs and improving early diagnosis are two critical steps to end the HIV and AIDS epidemic by 2030, according to a UNAIDS report. While HIV and AIDS still remains the leading cause of death among women ages 15–49 globally, there has been notable and sustained momentum toward ending the disease. Approximately 21 million people globally currently receive life-saving ARV treatments, with the number of people under treatment nearly doubling in the past five years. Significant cost reduction of ARV therapies as well as the sustained use of treatments have led to a 48 percent decline in AIDS-related deaths, from 1.9 million in 2005 to 1 million in 2016. UNAIDS officials emphasized that despite this progress, the world must not become complacent, as 17 million people are still waiting for treatment and a decline in global support could lead a rebound in the epidemic. Researchers at The University of Texas, El Paso have developed a potential vaccine for cutaneous leishmaniasis, a painful neglected tropical disease with an estimated 700,000 to 1 million new cases annually. While leishmaniasis predominantly affects the poorest countries in the world, the disease has also impacted over 2,000 US service members stationed in Afghanistan and Iraq, as well as residents in Texas and Oklahoma, where the disease occurs naturally. Researchers found that the vaccine candidate resulted in a 96 decrease in leishmaniasis-associated lesions and an 86 percent protection rate against the disease in mice studies. Though more research is necessary, researchers feel optimistic about this formula. There is no current vaccine for the disease in humans and current treatment options available are limited, painful, and lengthy.